580,5

FB

V, 4:2-9

1919-1929

cop, 2

FIELD MUSEUM OF NATURAL HISTORY.

PUBLICATION 204.

BOTANICAL SERIES. VOL. IV, No. 2.

BY

CHARLES FREDERICK MILLSPAUGH

AND

EARL EDWARD SHERFF.

CHARLES FREDERICK MILLSPAUGH

Curator, Department of Botany.

CHICAGO, U. S. A.

April, 1919.

Dup.

FIELD MUSEUM OF NATURAL HISTORY.

t \

PUBLICATION 204.

BOTANICAL SERIES. VOL. IV, No. 2.

REVISION OF THE NORTH AMERICAN

SPECIES OF XANTHIUM

BY

CHARLES FREDERICK MILLSPAUGH

AND *

EARL EDWARD SHERFF.

CHARLBS FREDERICK MILLSPAUGH

Curator, Department of Botany.

JUL

UNIYERSJiy Of

CHICAGO, U. S. A.

Issued April 30, 1919.

PV~£-

REVISION OF THE NORTH AMERICAN

SPECIES OF XANTHIUM

CHARLES F. MILLSPAUGH, M.D., and EARL E. SHERFF, Ph.D

The monographic study of the genus Xanthium is involved in

difficulties not only as to bibliography but also as to species concept.

Thanks to the kind and hearty co-operation of various botanists, we

have been able to settle very satisfactorily the numerous matters of

bibliography. The species concept in Xanthium, however, must long

remain a perplexing problem. In temperate regions, the plants do

not mature their fruits sufficiently for exact determination until after

frost comes and the majority of collecting botanists have ceased their

field-work. This renders good material in herbaria scanty in quantity

and inadequate in quality. Some of the species are known to exhibit

most striking variations in fruiting characters, — variations that with

many botanists would be taken to represent varieties or subspecies.

In fact, several of the more pronounced of these forms have been made

the basis of new species by certain authors, notably Greene (e.g.,

X. acutum, X. affine, X. calif ornicum, X. glanduliferum) . In the present

monograph the writers have endeavored to be neither hasty in the

proposal of new specific names nor radical in the reduction of old

names to synonomy. The taxonomic treatment has been made to

accord as strictly as possible with the observed data. We have retained

several of the less well known species (e.g., X. acerosum, X. cylindricum,

X. globosum, species that with some botanists might be reduced to

varietal or subspecific rank), because we have felt that only after fur-

ther field observations and breeding tests can satisfactory conclusions

as to their true status be reached.

Many of the numerous references in literature have necessarily been

omitted in the main body of our text: for a large number of these

references the reader is directed to De Candolle's Prodromus

(6:522-524. 1836) and to Wallroth's Monograph of Xanthium (Beitr.

Bot. i": 229-244. 1844). Since the publications of De Candolle

and of Wallroth, several other more or less extended studies of the

genus have been made: In 1893, Rowlee (Bull. Torr. Bot. Club 20: 10),

writing upon the seedling development of Xanthium, noted that "both

io FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

achenes in a single head frequently germinate, usually not at the same

time however, so the seedlings will be at two stages of growth." In

1895, Arthur (Proc. Soc. Prom. Agricult. Science 16:70-79) remarked

upon the inequality in size between the two achenes in the burs of

Xanthium and the delayed germination of the smaller one. Arthur

stated (loc, tit., p. 77) that "the bur with its contents is the physiological

equivalent of an achenium." Later, Masterman (Ohio Nat. 1:69-70.

1901) published observations upon several thousand specimens which

showed results directly opposite to those of Arthur (thus, of 3000 burs,

2751 produced two plants each, at the same time).

In 1906, Crocker (Bot. Gaz. 42:265-291), writing upon delayed

germination of seeds, treated of the physiological conditions of delayed

germination of Xanthium seeds. In 1908, Bitter, who had been inspired

by the early observations of Lasch (Bot. Zeitung 14:409. 1856) to

undertake careful cultural researches upon certain species of Xanthium,

was able to describe several pronounced races of X. italicum and of

X. spinosum. His numerous attempts at crossing X. spinosum with

species of the Section Euxanthium had been in vain. Thus he states

(Abhandl. Nat. Ver. Bremen 19": 291. 1908): "Bastarde lassen sich

nach meinen Erfahrungen zwischen den Euxanthien leicht erzielen,

wenigstens habe ich X. macrocarpum DC. und X. italicum erfolgreich

mit X. strumarium gekreuzt; dagegen waren meine vielfachen Versuche,

X. spinosum mit Euxanthien zu kreuzen, erfolglos."

Somewhat later in the same year, Thellung (Verhandl. Bot. Verein

Brandenb. 50": 137-151; see also Mitteil. Bot. Mus. Univ. Zurich 58:

505-512. 1912) published a very comprehensive survey of the botanical

literature relating to X. orientale L. and X. echinatum Murr. Thellung's

concept of these two species was so broad that his treatment of them

was stretched almost into monographic proportions. His work in the

herbarium seems to have been far less extensive than his work in the

library. We are not able otherwise to explain many of his numerous

equations of species with each other, — species which in several in-

stances are so strikingly unlike in fruit characters that we are entirely

unable to accept their reduction to synonomy by Thellung.

In 1911, Shull (Bot. Gaz. 52:453-477) published his investigations

upon the oxygen minimum and the germination of Xanthium seeds.

Later, in 1914, the same writer (Bot. Gaz. 57 : 64-69) presented fur-

ther data obtained along these lines. Likewise in 1914, Dalbey (Kansas

Univ. Science Bull. 9 : 57-65 and pis. 16-22) enumerated various

anatomical characters of X. pennsylvanicum, X. americanum [ = X.

chinense] and X. globosum. She states that these three species "pre-

sent some striking external characteristics, while in their anatomy there

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. n

are some definite but minor differences which might prove of uncertain

value in classification." The following year Fair described and illus-

trated the origin of the inflorescences of Xanthium (Bot. Gaz. 59:

136-148 and pi. 10. 1915). Several interesting conclusions are stated

by Fair. Among these, we note (he. cit., p. 145) that the "terminal

heads became staminate, because the vascular supply was inadequate

to compensate for the excessive transpiration, and hence the pistils

have aborted"; also that "the bur is a modified capitulum, differing

from the typical head of Compositae chiefly in the two depressions in

the receptacle. These pits originate through a temporary arrest of

development, which may possibly be attributed to contact with the

tips of the recurved involucral bracts. This recurving of the bracts

may be the result of limited space due to the subtending structures."

Throughout the prosecution of our own study, we have received the

most generous assistance from other botanists, both in America and

in Europe. It is with a sense of genuine pleasure that we express our

gratitude for such help, which usually consisted either in loaning

herbarium material, in furnishing photographic reproductions of de-

scriptions and plates, or in extending to us various herbarium facilities.

Chief among those to whom we are thus indebted are Prof. August©

Be*guinot, Director, R. Orto Botanico, Padua; Dr. Ezra Brainerd of

Middlebury, Vermont; Dr. N. L. Britton, Director of the New York

Botanical Garden; Miss Mary A. Day, Librarian of Gray Herbarium;

the late M. Casimir De Candolle, of Geneva; Mrs. Nellie F. Flynn of

Burlington, Vermont; Dr. J. M. Greenman, Curator of the Herbarium

of the Missouri Botanical Garden; Dr. H. M. Hall, of the University

of California; Professor James M. Macoun, of the Canadian Geological

Survey; Mr. Wm. R. Maxon, Associate Curator of the United States

National Herbarium; Dr. George T. Moore, Director of the Missouri

Botanical Garden; Dr. Julius A. Nieuwland, of the University of Notre

Dame (in charge of the Greene Herbarium) ; Sir David Prain, Director

of the Royal Botanical Gardens at Kew; Dr. A. B. Rendle, of the

British Museum of Natural History; Dr. B. L. Robinson, Curator of

Gray Herbarium; Dr. C. A. Shull of the University of Kentucky, and

Miss Ethelyn M. Tucker, Librarian of the Arnold Arboretum.

Upwards of two hundred photographs were made of the more im-

portant specimens examined in other herbaria during the progress of

the work. These, together with full data, are deposited in the herb-

arium of this Museum.

12 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

ABBREVIATIONS USED FOR HERBARIA

Hb. Calif. Herb. University of California

Hb. Can. Herb. Canadian Geological Survey

Hb. Chi. Herb. University of Chicago

Hb. Field Herb. Field Museum of Natural History

Hb. Mo. Herb. Missouri Botanical Garden

Hb. N. Y. Herb. New York Botanical Garden

Hb. U. S. United States National Herbarium

Xanthium (Tourn.) Linn. Sp. PI. 987. 1753

[Tourn. Instit. tab. 252, 1700. Linn. Gen. PI. 424, 1754]

Herbae annuae, ramosae, crassae, plerumque scabridae aut spinosae,

monoicae, sporadicae. Folia alterna, petiolis tenuibus petiolata, plus

minusve lobata aut rarissime inciso-divisa, plerumque punctis resinosis

parvis numerosis punctata. Capitula discoidea, homogama. Involucra

mascula summa, subglobosa, multiflora, bracteis liberis i-3-seriatis;

receptaculo cylindraceo, paleaceo; corollis tubulosis, clavatis, apice

5-dentatis; staminum filamentis monadelphis, antheris liberis, con-

niventibus, basi ecaudatis, appendicibus apicalibus incurvato-mucro-

natis; stylo simplici, tenue, ad apicem plus minusve dilatato; achaenio

rudimentario. Involucra feminea gamophylla, clausa aut rare sub-

clausa, cylindrica aut ovoidea aut etiam subglobosa, hamato-aculeata

aut rarissime simpliciter aculeata, ad apicem 2-rostrato (in Sect. II,

Acanthoxanthio, uno aut duobus rostris saepius absentibus); intus

2-loculare; corollis absentibus; styli ramis e rostris exsertis; acheniis

linearibus aut etiam ovatis, compressis, plus minusve crassis, ad apicem

tenuiter rostratis, levibus, singulis in loculis singulis inaequalibus

involucri maturatis et manentibus.

CLAVIS GENERIS

Folia attenuata utrinque; axillis spinis tripartitis munitis; aculeis ad

apicem cygneo-hamatis i. X. spinosum

Folia cordata, ovata aut subtriangulata; axillis inermibus; aculeis ad

apicem rectis aut simpliciter hamosis:

Fructus maturi plerumque maximi, aculeis et rostris adjectis

2.8-4 cm. longi et 2-3 cm. lati:

Aculei plerumque arcuati et corniformes, subcrassi:

Aculei saepius numerosi et conferti, teretes 2 1 . X. campestre

Aculei plerumque pauciores et remoti aut subremoti, infimi

ad faciem ventralem canaliculati 19. X. oviforme

Aculei non perspicue arcuati nisi ad apicem

hamosum, tenues 20. X. speciosum

Fructus maturi minores:

Aculei pauci et remoti (20-50) :

Fructus magni, corpore 1.5—1.7 cm. longo et 6-7 mm. lato;

aculeis 8-10 mm. longis 10. X. cenchroides

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 13

Fructus minores :

Fructi maturi subvirides 2. X. stramarium

Fructi maturi plerumque flavidi aut rubri:

Fructus corpus anguste cylindricum:

Aculei recti ad apicem hamosi 8. X. leptocarpum

Aculei dimidio supero flexi 7. X. curvescens

Fructus corpus ovatum aut oblongum:

Aculei cartilaginei, crassi, fructus cor-

pore tire. 8 mm. crasso 13. X. calvum

Aculei subtenues, fructus corpore pler-

umque 5-6 mm. crasso 9. X. Wootoni

Aculei plures:

Fructi glabri aut subglabri:

Fructus corpus plerumque cylindricum:

Folia acute lobata; fructibus venustis; aculeis tenuibus,

2-5~3-5 mm- longis 4. X. cylindricum

Folia subobtuse lobata; fructibus crassioribus; aculeis

crassioribus et saepius 3.5-7 mm. longis

12. X. pennsylvanicum

Fructus corpus plerumque crasso-ovoideum aut subglo-

bosum:

Rostra elongata (6-9 mm. longa); species mexicana et

austro-americana 15. X. australe

Rostra non elongata (3-4 mm. longa);

species boralior 5. X. globosum

Fructus corpus ovato-oblongum:

Aculei breves (saepius tire. 2 mm. longi),

basi dilatati 14. X. palustre

Aculei longiores, basi non perspicue dilatati:

Rostra brevia (circ. 2 mm. longa), crassa

2. X. strumarium

Rostra longiora (3-6 mm. longa), tenuiora:

Aculei conf erti, arcuati :

Quidam aculei ad fructus rostra longissimi (8-10

mm.) ; rostris 5-7 mm. longis n. X. inflexum

Aculei aequales aut subaequales (4-6 mm. longis) ;

rostris 3.5-5 mm. longis 6. X. arcuatum

Aculei remotiores, recti 3. X.' chinense

Fructus plus minusve setosi, hispidi aut pilosi:

Aculei fructuum maturorum dense, longe et molliter fusco-

pilosi 1 8. X. acerosum

Aculei fructuum maturorum setosi aut hispidi sed non vere

longo- et molli-pilosi :

Fructus 8-1 2 mm. longi ; aculeis tircum 2 mm. longis (specie

maximam partem gerontogaea) 2. X. strumarium

Fructus et aculei longiores :

Aculei valde hispidi:

Corporis latitude quam longitudo

circ. dimidio minor 16. X. echinatum

Corporis latitude etiam minor 17. X. italicum

14 FIELD MUSEUM OP NATURAL HISTORY — BOTANY, VOL. IV.

Aculei non valde hispidi.

Quidam aculei ad fructus rostra longissimi (8-10

mm.) ii. X. inflexum

Aculei aequales aut subaequales:

Corpus globoso-ovatum, rostris elongatis

15. X. australe

Corpus plerumque angustius, rostris non perspicue

elongatis 12. X. pennsylvanicum

Sect. I. ACANTHOXANTHIUM DC. Prodr. 5 : 523. 1836; Acanihoplia

Wallr., Beitr. Bot. in : 241. 1844; Acanthoxanthtum Fourr.,

pro genere, Ann. Soc. Linn. Lyon., N. Ser. 17 : no. 1869. Invol-

ucri fructigeri rostrum saepius unicum aut nullum; fructibus

apice conniventibus, clausis; spinis validis ad basim foliorum;

foliis numquam cordatis sed basi cuneatis.

i. XANTHIUM SPINOSUM Linn. Sp. PI. 987. 1753.

Xanthium xanthocarponWallr. Beitr. Bot. in:24i. 1844.

Acanthoxanihium spinosum Fourr. Ann. Soc. Linn. Lyon., N. Ser.

17 : no. 1869.

Caulis pubescens, ramosus, erectus aut ascendens, 3-12 dm. altus.

Folia lanceolata aut ovato-lanceolata, petiolata, utrinque acuminata

aut acuta, 2-4-lobata aut supera integra, infra et ad venas supra

canescentia, petiolis adjectis 4-12 cm. longa, axillis spinis gilvis tri-

partitis usque ad 2.5 cm. longis munita; petiolis 0.5-2 cm. longis.

Fructus (PI. VII, f. i; PI. VIII, ff. 1-3) oblongo-cylindrici, plerumque

flavido-virides, pubescentes; rostris tenuibus, levibus, acribus, circ.

3 mm. longis, plerumque uno et saepe etiam duobus absentibus; aculeis

distinctis aut remotis, ex apice cygneo-curvato in hamum inflexum

quartam aculei partem desinentibus.1

DISTRIBUTION: Now generally distributed almost throughout the

United States; found also in South America, where probably native,2

central Europe, "western Asia, southern Africa and in Australia."

SPECIMENS EXAMINED :3 NEW YORK: without locality or date,

M. Ruger (Hb. Mo. 720720). NEW JERSEY: Camden, Aug., 1878,

Isaac C. Martindale (Hb. Mo. 720837). DISTRICT OF COLUMBIA: vicin.

of Washington, waste ground, E. S. Steele 43 (Hb. Mo. 85567 and

85568). VIRGINIA: Bedford County, A. H. Curtis 3472 (Hb. Mo.

85569); Wythe County, Reed Creek, at base of lower rocks, July 23,

1892, John K. Small (Hb. Mo. 85570). FLORIDA: Apalachicola, without

date, Dr. A. W. Chapman (Hb. Mo. 783796). ILLINOIS: Mound City,

1 It may be remarked that in the description we have omitted all reference to

achene characters. As the characters of the achene can not be described satisfac-

torily from fruits not known to be mature, and as thoroughly mature fruits have

not, in all species, been available for dissection, it has been deemed best to omit

these characters from all of the specific descriptions.

2 Cf. Thellung, Mitteil. bot. Mus. Univ. Zurich 58 : 505. 1912.

* Many omitted here for lack of space.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 15

without date, George Vasey (Hb. Field 13470). KENTUCKY: Bowling

Green, Oct., 1899, Sadie F. Price (Hb. Mo. 85573). TENNESSEE:

Knoxville, vacant lots, July, 1893, A. Ruth (Hb. Mo. 720836). MIS-

SOURI: St. Louis, Oct. 23, 1893, H. Eggert (Hb. Mo. 85575, 720560 and

720835). TEXAS: Handley, Sept. 23, 1902, /. Reverchon (Hb. Mo.

85580). NEW MEXICO: near Pecos, Paul C. Standley 5150 (Hb. Mo.

85582; Hb. N. Y.). NEVADA: Verdi, Oct., 1893, C. F. Sonne (Hb. Calif.

196334). ARIZONA: Prescott, David Griffiths 7344 (Hb. Mo. 85583).

VANCOUVER ISLAND: Nanaimo, July 7, 1887, John Macoun (Hb. N. Y.).

WASHINGTON: Walla Walla, July, 1898, Savage, Cameron and Lenocker

(Hb. Mo. 85584). CALIFORNIA: Los Angeles, Le Roy Abrams 4181

(Hb. Calif. 149138; Hb. Mo. 85589; Hb. N. Y.); Sherman, Ernest

Braunton 731 (Hb. Calif. 54178); vicin. Mendocino, H. E. Brown 919

(Hb. N. Y.); near Yreka, Geo. D. Butler 991 (Hb. Calif. 163874);

Colusa County, ]. Burtt Davy 4277 (Hb. Calif. 36807) ; near Durham,

roadsides and fields, A. A. Heller 12655 (Hb. Mo. 802945); San Simeon

Bay, July 22, 1876, Dr. Edw. Palmer (Hb. Mo. 85587); Haywards,

Nov. 14, 1893, Ivar Tidestrom (Hb. Calif. 36806); Avalon, Santa Cata-

lina Isl., Aug., 1902, Blanch Trask (Hb. N. Y.).

Wallroth (loc. cit.} founded his Xanthium xanthocarpon upon a

specimen by Beyrich, from fields between Staunton and Charlottesville,

Virginia. The distinctive characters tabulated in his description are

entirely too inconstant, however, to serve in distinguishing the species

from true X. spinosum L. Thus, for example, Wallroth described the

beaks as unequal, the larger one twice stouter than the prickles:

("Rostris inaequalibus, majore aculeis duplo validiore"). In the

nearly two hundred specimens of X. spinosum which we have examined,

from North America, we have seen several that matched Wallroth's

description in these and other respects precisely. Nevertheless these

specimens were but slight variations from the more common, short-

beaked form regarded by Wallroth as representing the true Xanthium

spinosum L.

Sect. II. EUXANTHIUM DC. Prodr. 5 : 523. 1836; Anoplia Waltr.

Beitr. Bot. in: 229. 1844. Involucri fructigeri rostra apice nunc

recta (Tribus I. Orthorrhyncha Wallr. loc. cit.}, nunc in hamum

varie inflexum desinentia (Tribus II. Campylorrhyncha Wallr.,

loc. cit.}, nunc hiatu longitudinali magis minusve contracto reclusa

vel teretia, nunc transversim fissa, veluti bivalvia; caulibus erectis

saepius purpureo-maculatis; foliis dentatis; spinis ad basim foliorum

nullis.

16 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

2. XANTHIUM STRUMARIUM Linn. Sp. PI. 987. 1753.

Xanihium priscorum Wallr. Beitr. Bot., iu: 227. 1844. (nom.

semi-nudum.)

Xanihium antiquomm Wallr. loc. cit. 229

Xanihium strumarium L. var. antiquorum (Wallr.) Ball, Jour.

Linn. Soc. 16 : 503. 1878.

Xanihium abyssinicum Wallr. loc. cit. 230.

Xanihium discolor Wallr. loc. cit. 232.

Xanihium Roxburghii Wallr. loc. cit. 233.

Xanihium brevirostre Wallr. loc. cit. 235.

Caulis subramosus, pubescens*, 0.4-1.5 m. altus. Folia triangulato-

deltoidea et ad basim truncata aut subcordata, 3~5-lobata, utrinque

pilis adpressis strigosis vestita et concoloria, petiolis adjectis 0.6-2.5 dm.

longa; petiolis laminas subaequantibus aut excedentibus. 'Fructuum

(PI. VII, f. 2; PI. VIII, ff. 4-8) corpus ovoideum, aut tumidum et

subglobosum, plerumque subviride, pubescens, 0.8-1.4 cm. longum;

rostris versus apicem rectis aut incurvatis, 1-2 mm. longis, saepius

distantibus; aculeis rectis, ad apicem hamosis, supra glabris, infra plus

minusve pubescentibus, circ. 2 (rarius 3) mm. longis.

DISTRIBUTION: Adventive in Massachusetts and California; native

of the north-temperate and tropical regions of the Eastern Hemisphere.

SPECIMENS EXAMINED: MASSACHUSETTS: Revere, Crescent Beach,

Oct. 20, igi2,M.L.Fernald (Hb. Gray). CALIFORNIA: Colorado Desert,

Cameron Lake, Mar. 28, 1901, T. S. Brandegee (Hb. Calif. 131246).

We have already (Field Mus. Bot. 4:2. 1918) noted the collection

of genuine X. strumarium in North America, by Fernald, in 1912. It is

of interest to note that, several years earlier, this species was collected

in the extreme southern part of California, by Brandegee. We have not

seen the species from elsewhere in America.1

In 1830 Rafinesque listed (Med. Fl. 2 : 275) "2 native species

Xanthium crassum and undulatum Raf. mistaken for X. strumarium

and orientale by authors." Thus Rafinesque is seen to have realized,

at an early date, that the common forms of Xanthium in America were

not referable to X. strumarium and X. orientale (see p. 26, foot-note).

Rafinesque's two names appear to have been ignored, or indeed over-

looked, by botanists since then. But obviously these names can be

treated only as nomina nuda, for their precise application to definite

American species is impossible. Characteristically, in this connection,

Rafinesque fails to mention his own Xanthium maculatum, described,

in detail, from the eastern United States eleven years before. There

exists, in Gray Herbarium, a good co-type of X. abyssinicum Wallr.

(W. Schimper 1343). This specimen we are entirely unable to separate

_ 1 At least as an escaped plant. We have seen good fruiting material however,

raised by Dr. John M. Adams at Cincinnati, Ohio, in 1918, from seed imported with

soy-beans from Manchuria (specimen in Hb. Ohio Agr. Exp. Station).

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 17

from X. strumarium L.; in the same herbarium is a specimen (Kotschyi

iter Nubicum 319, ad ripas Nili albi prope Chartum in provincia Sennar,

Mar. 4, 1840) which has slightly longer and more numerous prickles,

these more hirsute below than in most other specimens. This is the

form cited by Wallroth for his X. antiquorum.1 It is matched very well

by a fine specimen in the Herbarium of Field Museum (Fred S. Meyers

215, waste places, Jaffa, Aug. 2, 1902, Hb. Field 162920) coming from

Palestine. The distinctions emphasized appear to us, however, too slight

and inconstant to warrant maintaining X. antiquorum apart from X.

strumarium. Likewise, after examining a number of specimens from

India (mainly in Hb. Gray) we are convinced that X. discolor Wallr.,

X. Roocburghii Wallr. and X. brevirostre Wallr. are merely forms of

X. strumarium L. (as indeed they were regarded by Hooker, Fl. Brit.

Ind., 3 : 303. i88i).2

3. XANTHIUM CHINENSE Mill. Gard. Diet. Edit. VIII, No. 4. 1768.

Xanthium chinense Mill. Abridg. Gard. Diet. Edit. VI, No. 4.

1771.

Xanthium occidentale Bertol. Lucubr. Herb. 38. 1822.

Xanthium macrocarpum var. glabratum DC. Prodr. 5 : 523. 1836.

ex. descr.

Xanthium pungens Wallr. Beitr. Bot. in: 231. 1844.

Xanthium longirostre Wallr. loc. cit. 237; Britton Fl. Bermuda 384,

f. 417. 1918.

Xanthium glabratum Britt. Man. 912. 1901.*

1 Xanthium priscorum Wallr. (loc. cit. 227). Wallroth used the name X. priscorum

in his clavis, accompanying it with a short diagnosis; but in the main body of his work

and also in the introduction (pp. 221 and 229) he had changed the name to X. anti-

quorum. His retention of the name X. priscorum was clearly through an oversight.

We may note a similar error in regard to his X. eriocarpon (which is referable to

X. ambrosioides Hook. & Arn., for which species Wallroth merely made a new, and

in his opinion, more accurate name; we have seen various excellent specimens in

Hb. Gray and Hb. N. Y.). Wallroth at first (loc. cit. 229) advanced this species in

his clavis under the name X. leucocarpon, with a short diagnosis; but in the main

body of his work (p. 242) he had changed the name to X. eriocarpon.

1 Xanthium inaequilaterum DC., a species with smaller fruits (5-6 mm. long

exclusive of the beaks), originally described from material collected near Buitenzorg,

Java, is similar to X. strumarium, but its smaller fruits are very distinctive. Several

good (topotypic) fruiting specimens exist in Hb. Gray (Zollinger, Batavia, Java, in

1849; Teysmann, ex horto bogoriensi, Buitenzorg, Java, in 1869). These are re-

markably uniform and appear to indicate that the species X. inaequilaterum DC.

is entirely separate from X. strumarium L.

A number of other species of Xanthium have been described from the Eastern

Hemisphere that undoubtedly are mere forms of X. strumarium; however, as

opportunity has been lacking to examine authentic material, their names have been

omitted from our list of synonyms.

lXanthium canadense of Rowlee, not Miller, Bull. Torr. Bot. Club 20 : 10, ff.

g-m. 1893.

f Xanthium carolinense Dill, ex MacMillan, Geol. Nat. Hist. Surv. Minn. Bot.

i : 535- 1892. We have not seen the original work of Dillenius, cited by

MacMillan, for this reference.

Xanthium strumarium of Millsp. & Chase, Field Mus. Bot. 3 : 87, f. 1904.

Xanthium strumarium of Britton & Brown, 111. Fl. 3 : 298, f. 3599. 1898. See

also footnote, p. 40.

1 8 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

Caulis scaber, 0.3-1 (aut etiam-2) m. altus. Folia late triangulato-

orbiculata, acute 3-5-lobata, subacute dentata, ad basim cordata aut

reniformia, plerumque submembranacea, utrinque concoloria et pilis

setosis adpressis brevissimis vestita, petiolis adjectis 1-3 dm. longa,

inferiora interdum 2.5 dm. lata, petiolis laminis subaequantibus.

Fructus (PI. VII, f. 3; PI. VIII, ff. 9-15) ovoidei aut fusiformes, calves-

centes, aequaliter et conformiter aculeati, fusco-virides aut rubescentes;

corpore sparsissime brevi-pubescenti, glanduloso, 0.9-1.5 cm. longo

(rarius longiore); rostris rectis aut arcuatis, infra pubescentibus, ad

apicem inflexis aut infirme hamosis, 3-6 mm. longis; aculeis glabratis

aut ad basim sparsim glanduloso-pubescentibus, rectis, ad apicem hamo-

sis, rostris aequantibus.

DISTRIBUTION: Massachusetts, Ontario and Nebraska, to Florida,

Texas and California (where very rare) ; eastern Mexico and throughout

the West Indies.

SPECIMENS EXAMINED:1 MASSACHUSETTS : Wayland, Sept. 10, 1909,

M. L. Fernald (Hb. Gray). CONNECTICUT: Goshen County, wet ground,

Sept. 18, 1905, C. H. Bissell (Hb. Gray) ; West Hartford, border of pond,

Oct. 14, 1906, idem (Hb. Gray). NEW YORK: Long Island, Lakeville,

waste place, Sept. 25, 1899, /. R. Churchill (Hb. Gray) Canton, banks

of Grass River, Mrs. Orra Parker Phelps 980 (Hb. Gray) ; Ogdensburg,

along banks of St. Lawrence River, eadem 1215 (Hb. Gray; an unique

form with abnormally large fruits having bodies 1.9-2.4 cm. long and

7.5-9.5 mm. thick). PENNSYLVANIA: near Philadelphia, John H. Red-

field 3475 (Hb. Mo. 85397). MARYLAND: Plummer's Island, in Potomac

River, near Cabin John, Thomas H. Kearney 193 (Hb. U. S. 640356);

shore of Chesapeake Bay, south of Havre de Grace, George H. Shull 392

(Hb. Gray; Hb. Mo. 85399). DISTRICT or COLUMBIA: Washington,

Charles L. Pollard 718 (Hb. U. S. 234642). VIRGINIA: Bedford County,

Oct. 10, 1871, A. H. Curtiss (Hb. Gray); Altavista, waste land, Juliet

Fauntleroy 677 (Hb. U. S. 754995). NORTH CAROLINA: Buncombe

County, roadside near Black Mountain, Standley and Bollman 10301

(Hb. U. S. 689122). FLORIDA: Lake City, anonymus (Hb. Fla. Agricult.

Coll. no. 1279 in Hb. Field 234909); Key West, sandy places near the

beach, J. K. Small 3720 (Hb. N. Y.; important as matching precisely

Greenman's no. 47, topotype of X. chinense from vicinity of Vera Cruz).

ONTARIO: Russell, near Nation River, July 28, 1911, John Macoun

(Hb. Mo. 719899). MICHIGAN: near Port Huron, roadside ditches,

C. K. Dodge 43 (Hb. Gray) ; near Port Huron, roadside ditches, idem 45

(Hb. Gray); near Port Huron, marshes, idem 48 (Hb. Gray). KEN-

TUCKY: Bowling Green, Aug., 1899, Sadie F. Price (Hb. Mo. 46001).

1 For lack of space many specimens examined must be omitted here. Our citations

are complete, however, as to the material examined from Mexico and the West

Indies.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 19

TENNESSEE: vicin. Smyrna, Sept. 7, 1898, H. Eggert (Hb. Mo. 85404

and 85405). WEST VIRGINIA: Sweetsprings, Steele and Steele 271

(Hb. Gray; Hb. Mo. 85401). ALABAMA: Auburn, in cultivated fields,

F. S, Earle 2202 (2 sheets in Hb. N. Y.); Auburn, Sept. 18, 1897, Earle

and Baker (Hb. N. Y.). ILLINOIS: St. Clair County, Indian Lake, Sept.

25, 1903, H. Eggert (Hb. Mo. 85420) j1 MISSOURI: Swan, B. F. Bush 589

(Hb. Mo. 85411); Courtney, in fields, idem 871 (Hb. Mo. 85407);

Courtney, in bottoms, idem 873 (Hb. Mo. 85410) ; Courtney, in bottoms,

idem 7809 (Hb. Mo. 809933) ; St. Louis, cultivated fields, especially in

rich land, Aug. 1845, Dr. George Engelmann (Hb. Mo. 85415 and 85416);

St. Louis, riverbanks, July, 1837, Carl A. Geyer (Hb. Mo. 85414);

Neck City, low ground, E. J. Palmer 1304 (Hb. Mo. 85421 and 756630);

Noel, Butler Creek, gravel bars, idem 4220 (Hb. Mo. 716541). Kansas:

Atchison County, in fields, A. S. Hitchcock 727 (Hb. Gray; Hb. Mo.

85424); Riley County, low ground, /. B. Norton 261 (Hb. Gray).

NEBRASKA: Red Cloud, .Rev. J. M. Bates 5450 (Hb. Gray). OKLAHOMA:

Sapulpa, B. F. Bush 298 (Hb. Mo. 85426). ARKANSAS: Fulton, in fields,

B. F. Bush 965 (Hb. Mo. 85422). LOUISIANA: Natchitoches, wet

ground, E. J. Palmer 8727 (Hb. Mo. 794561). TEXAS: Columbia, in

fields, B. F. Bush 1348 (Hb. Mo. 85428); Dallas, in fields, J. Reverchon

2591 (Hb. Mo. 85431; Hb. N. Y.). CALIFORNIA: Fort Yuma, Colorado

River bottoms, 5. B. Parish 8360 (Hb. Gray; — a puzzling specimen,

in some respects strongly suggesting X. strumarium L., which has been

collected west of here by Brandegee at Cameron Lake. See X. stru-

marium L.). MEXICO: La Laguna, near Vera Cruz, J. M. Greenman 47

(Hb. Field 189512; Hb. Gray). BERMUDA ISLS.: Devonshire, cultivated

ground, Brown and Britton 374 (Hb. Field 203890; Hb. Gray); waste

grounds near Tucker's Town, iidem 1724, (Hb. U. S. 758285). BAHAMA

ISLS. : Nassau, waste grounds, Britton and Brace 383 (Hb. Field 171815) ;

Nassau, Nov., 1890, A. S. Hitchcock (Hb. Field 174738). CUBA: Playa

de Cojimar, on coral limestone near the sea, Mar. 16-26, 1906, A. S.

Hitchcock (Hb. Field 235055); Prov. Havana, Santiago, plantations,

1 In the same herbarium (No. 759001) is another good specimen, by Eggert, from

waste places, vicinity of East St. Louis, Illinois, Oct. 14, 1886; on the same sheet with

it is a specimen, closely similar in habit and foliage, but in fruits approaching X.

pennsylvanicum Wallr. with which species it seems to be a hybrid. This second

specimen is identical with two others of the same date, by Eggert (Hb. Mo. 721197;

Hb. Gray). A fifth specimen of the same date and locality, likewise by Eggert

(Hb. Mo. 85526) is even more clearly a hybrid: its burs are fusiform, dark reddish-

brown, sparsely and inconspicuously glandular-pubescent, very sparsely aculeate,

with only about 25-40 uncinate, subglabrous (unless sparsely hispid at the base)

prickles, the body of the mature burs about 1.6 cm. long and 5.5 mm. thick; prickles

and beaks 4-6 mm. long; the achenes mostly abortive. The burs of this last speci-

men present in their technical characters a slight resemblance to those of X. Wootoni

Cockll. but this resemblance is very superficial and disappears upon visual comparison

of the two sorts.

20 FIELD MUSEUM or NATURAL HISTORY — BOTANY, VOL. IV.

H. A. Van Hermann 360 (Hb. Field 172254); without locality, in 1865,

C. Wright (Hb. Gray). SANTO DOMINGO: Sanchez, Rose, Fitch and Rus-

sell 4351 (Hb. U. S. 760483). PORTO Rico: Vieques Isl., Resolucion to

Punta Arenas, in sand, /. A. Shafer 2901 (Hb. U. S. 790346). ST. CROIX:

Alfred E. Ricksecker 266 (Hb. Field 70621). TORTOLA: Sea-cow Bay,

roadside, Britton and Shafer 928 (Hb. U. S. 756709). GUADELOUPE:

Pfre Duss 2816 (Hb. Field 202726).

Apparently no other species of Xanthium has offered heretofore so

baffling a problem concerning its true status as has this species. It has

been referred at various times to such species as X. strumarium L., X.

canadense Mill. ,X .americanum Walt. etc. From X. strumarium L. it differs

as a rule very distinctly in having the burs larger, smoother and greenish-

brown to reddish in color, not mostly yellowish-green; furthermore, the

beaks in X. chinense are longer. X. canadense, as we indicate else-

where (p. 26, foot-note)1 was merely X. orientale L., a species not known

authentically in America and differing from X. chinense in having

stouter, more coarsely hooked and more hispid prickles and more

arcuate beaks.

In 1768, Philip Miller (Gard. Diet. Edit. VIII, no. 4) advanced a

new species of Xanthium which he termed X. chinense. He described

the species briefly, "4. Xanthium (chinense) caule inermi ramosa, aculeis

fructibus erectis longissimis. China. Xanthium with an unarmed

branching stalk, and the spines of the fruit very long and upright."

He stated, in addition, that it grew "naturally in China from whence he

had received the seeds." But, on inspecting his description, we find it

to portray a species which no accounts show ever to have been collected

in China, or anywhere else in the Eastern Hemisphere. The nearest

approach to the description, as concerns the Orient, would be X.

strumarium L. However, not even the Egyptian form2 of X. stru-

marium, the form with spines longer than usual (2.5-3 mm.), has spines

so long as to explain or justify Miller's use of the word "longissimis."

It is very likely that this seemingly insurmountable discrepancy between

description and cited habitat has, in the past, entirely deterred botanists

1 We have already stated (Field Mus. Bot. 4: 2. 1918) that the name canadense,

advanced by Miller in the eighth edition of his Gardener's Dictionary, was equated

in the ninth (posthumous) edition with X. orientale L. We may note, further, that

Miller originally cited as a synonym of his species the diagnosis of X. orientale L.

and gave also "X. majus canadense H. L. 635" (Cf. Thellung,' Verhandl. Bot. Verein

Brandenb. 50": 139. 1908). But Thellung (loc. cit. 138) states in detail and, to us

very convincingly, the evidence that this "X. majus canadense H. L. 635" is merely

the X. orientale of Linnaeus. In fact, Linnaeus himself (Sp. PL Edit. II: 1400.

J763) cited "Xanthium majus canadense. Herm. lugdb. 635 " as the second synonym

of his X. orientale.

J X. antiquorum Wallr., found also in Palestine. Cf. p. 17.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 21

from attacking the status of X. chinense in a more than cursory

way.1

Fortunately for our purpose, however, there appeared in 1771, the

year of Philip Miller's death (fide Pritzel, Thesaurus 218. 1872) and

three years subsequent to the appearance of the eighth edition of The

Gardener's Dictionary, an Abridgement of Miller's Gardener's Dic-

tionary, sixth edition.2 In this abridgment, Miller introduced X.

chinense from his Gardener's Dictionary, eighth edition, retaining the

same peculiar description3 but omitting the word China. As we search

his supplementary text, we find a most interesting statement: "The

fourth sort [X. chinense] was discovered by the late Dr. Houston in

the year 1730, growing naturally at La Vera Cruz."

Now it happens that in 1906, Dr. J. M. Greenman spent some time

collecting in the neighborhood of Vera Cruz (Mexico) for Field Museum

and, during the course of his work, collected specimens of Xanthium

(Greenman 47) the fruits of which we find to match Miller's description

strikingly. The prickles are not strongly inbent, as in the X. orientale L.

that Miller knew, but erect ("erectis"). Nor are they short, as in the

X. strumarium L. known to Miller, but, by comparison, very long

("longissimis ").

It appears to us to be beyond all doubt that Miller had made the

acquaintance of this species in the prime of his life, during the period of

his greater literary activity, but had not published it; — that late in life

when seventy-seven years of age (fide Pritzel, Thesaurus 218. 1872),

he published an accurate though short Latin description under the

name X. chinense, thinking that to it belonged various Chinese speci-

mens sent to him; — and that finally, just before his death, he realized

his mistake in having referred Chinese specimens to the species and so,

with a view to clarity, actually stated that the original specimens came

from Vera Cruz.

An examination of the Greenman plants, which we may well take as

representing X. chinense, shows them to be the same species that grows

very commonly throughout the West Indies and which Bertoloni

1Wallroth (Beitr. Bot. in: 223. 1844) equated X. chinense with his X. dis-

color, which was a segregate from X. stramarium L. But Wallroth expressly stated

for his X. discolor that the prickles were short ("kurz und abstehend eingebogene

Stacheln")f whence it appears that he entirely ignored the character "longissimis"

given by Miller.

1 Regarding the extreme rarity of this work, see Thellung (Verhandl. Bot. Verein

Brandenb. 50°: 144. 1908). We have been fortunate in securing excellent copies

of the pertinent portions from the volume in the Library of the Arnold Arboretum,

handwritten for us by the Librarian, Miss Ethelyn M. Tucker.

1 Miller dropped the word ramosa after caule inermi and added the word simplici-

bus after erectis.

22 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

described from Santo Domingo in 1822, under the name X. occidental.1

Moreover it is the same which Wallroth, in 1844, named somewhat

provisionally X. longirostre. Wallroth very clearly voiced his hesitancy

in publishing a new name, but he had not seen authentic Santo Domingo

specimens of X. occidental with which to match his X. longirostre mate-

rial from St. Thomas and Haiti, so was constrained not to equate the

two names.

Specimens from the West Indies vary considerably in size of bur and

in curvature and length of beaks. Sometimes the prickles are slightly

short-hispid near the base, — not "simple" as described by Miller.

The Greenman plants exhibit this same small departure from the

original description. Commonly the burs are rather few, large, in

color greenish-brown. A character frequently observed, especially in

the West Indian material, is the peculiar appearance of many of the

burs, their beaks being long, not widely divergent, somewhat incurved

and suggesting the bill of a bird; this character is present on several

burs of the Greenman plants.

Specimens from continental North America usually have the burs

more numerous, smaller and more or less reddish in color. These speci-

mens harmonize very well with the description of X. pungens Wallr.,

but the intergradations between the continental and West Indian forms

are so numerous as to render vain all our attempts at separation.1

Hence we are compelled to regard X. pungens as merely a form or variety

of X. chinense.

In not a few cases, X. chinense appears from herbarium specimens, to

have formed hybrids with X. pennsylvanicum (cj. p. 19, foot-note). At

other times the fruits, varying to a coarse, more elongate, more hispid

type, display a very close approach to those of the same species, but

without suggestion of hybridity. On the whole, however, the two

species are very easily distinguishable.8

1 Raised from seed sent by Bertero from Santo Domingo. " Nux oblonga, medio

ventricosa, utrinque attenuata, muricata, aculeis raris, subulatis, uncinatis, gra-

cilibus, apice bi-trirostris, rostris convergentibus, viridis, vix puberula." (Bertol.

Lucubr. Herb. 38. 1822).

* Rydberg (Dr. Per Axel), also Wiegand (Dr. Karl M.) each of whom made a

somewhat extended preliminary study of the genus Xanthium and then postponed

or abandoned the investigation, appear to have met with the same result. Thus we

note on a sheet of typical West Indian material in Gray Herbarium (Brown and

Britton 374, Bermuda) the annotation in pencil by Rydberg, "X. americanum

P. A. R." and, by Wiegand, "X. pungens Wallr. K. M. W." By X. americanum,

Rydberg meant, as his other herbarium annotations show, the X. pungens of Wall-

roth, which had of late been referred (by Britton and Brown, Illustr. Fl. Edit. II.

3: 346, f. 4139) to the enigmatic X. americanum Walt.

1Thellung (Verhandl. Bot. Verein Brandenb. 50°: 144. 1908) equates X.

pennsylvanicum Wallr., X. occidental Bertol. and various other names categorically

with X. echinatum Murr. The chinense of Miller he resolves into two parts, regarding

the first or supposedly Chinese form as a variety of X. strumarium L. and referring

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 23

4. XANTHIUM CYLINDRICUM Millspaugh and Sherff, Field Mus. Bot.

4 : 4, PL 3. 1918.

Caulis scabridus, verisimiliter 0.5-1.5 m. altus. Folia magna,

quibusdam foliis Hibisci militaris Cav. simillima, subdeltoideo-ovata,

trilobata (et fere hastata) aut quinquelobata, margine dentata, basi

cordata aut subtruncata, membranacea, scabra aut tactui etiam fere

levia, setulis adpressis minutis vestita, petiolis adjectis 1.3-2.5 dm.

longa, petiolis laminis subaequantibus. Fructuum (PL VII., f. 4;

PL VIII., ff. 16-20) corpus cylindrico-fusiforme, rubro-badium, glandulis

minutis punctatum, aliter glabrum, 1.4-1.6 cm. longum et 4-5 mm.

crassum; rostris arcuatis, ad apicem hamosis, glabratis, 4-5 mm. longis;

aculeis tenuibus, rubro-badiis, ad apicem hamosis, glabratis, 2.5-3.5 mm-

longis.

DISTRIBUTION: North Carolina.

SPECIMENS EXAMINED: NORTH CAROLINA: Chimney Rock to Hen-

dersonville, Oct. 3, 1901, J. K. Small and A. M. Huger (Hb. Field 401312,

type; Hb. N. Y., cotype).

When this species was originally described, there was no question

with us as to the soundness of the policy pursued by certain authors of

regarding West Indian and United States specimens of X. chinense as

specifically distinct. But since then, our studies have convinced us, as

stated under X. chinense, that the United States specimens formerly

referred to X. americanum (Auct. amer., forsan non Walt.; X. stru-

marium Auct. amer. ex parte, non L.; X. pungens Wallr.) represent

merely an inconstant race or variety of the West Indian and Mexican

X. chinense. This being true, there arises the question as to whether

X. cylindricum likewise may not indeed prove to be a race of X. chinense.

So far, however, we have been unable to find intermediate specimens

that seemed to connect adequately with X. chinense.1 Hence we are

constrained to reserve judgment in the matter until future studies shall

have thrown more light upon the true status of this form.

5. Xanthium globosum Shull sp. nov. (Cf. Dalbey, Kansas Univ.

Science Bull. 9: 57. 1914; Shull, Bot. Gaz. 59: 474-483. 1915.)

Caulis rubro-purpureus aut stramineus, saepe longitudinaliter pur-

pureo-punctatus, 3-10 dm. altus; ramis demum (in speciminibus robus-

the second or Mexican form to X. echinatum Murr. Clearly, Thellung was totally

lacking as to a proper conception of X. occidentale ( = X. chinense), a species that,

under various names, has become uniformly recognized in recent decades by promi-

nent American authors as a valid species. Furthermore, even were Thellung1 s treat-

ment correct and the first X. chinense (published in 1768) reduced to synonomy with

X. strumarium L., then the second X. chinense (published in 1771), based according

to Thellung upon a different plant and being according to Thellung an entirely different

species, would become valid and would take precedence over the name X. echinatum

Murr. which Thellung maintains (Cf. Internat. Rules Bot. Nomencl. art. 50. 1906).

1 We have found two specimens of X. chinense from Missouri (Webber, roadsides,

West St. Louis, Oct. 14, 1890, Hb. Mo. 46000 and 85413) that show small leaves

suggestive in form and color of the larger ones on X. cylindricum.

24 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

tis) plus minusve elongatis, imis etiam i . i m. longis. Folia non perspicue

crassa, subdeltoidea, tri-aut quinquelobata et basi cordata, serrata,

utrinque setulis adpressis scabra, petiolis adjectis 0.7-2.3 dm. longa,

petiolis laminis subaequantibus. Fructus (PI. VII., f. 5; PL VIII.,

ff. 21-23) saepe numerosi (circum 1850 in uno specimine observatis, ex

littera Shullii) ; corpore late ovoideo aut subgloboso, vix pubescenti sed

glandulis minutissimis numerosis vestito, 0.9-1.1 cm. longo et 4.5-7 mm.

crasso; rostris rectis aut non ranter arcuatis, 3-4 mm. longis; aculeis

levibus et rectis sed ad apicem hamosis, rostris subaequantibus.

DISTRIBUTION: Missouri and Kansas.

SPECIMENS EXAMINED: MISSOURI: Randolph, "a very common

weed," Kenneth K. Mackenzie 387 (Hb. Mo. 85408); Jasper County,

La Russel, in waste places along railroads and in fields, Ernest J. Palmer

1301 (Hb. Mo. 46004 and 756629). KANSAS: Lawrence, breeding

grounds of Univ. of Kansas, Sept., 1913, from original plants obtained

on northern edge of Wakarusa flood plain about 0.5 km. south of

Mount Oread, Charles A. Shull (type in Hb. Field 477325); Lawrence,

breeding grounds of Univ. of Kansas, Sept., 1917, idem (Hb. Field

477328; lineal descendant from type material); Lawrence, in 1917, idem

(Hb. Field 477326; burs from typical plant growing wild); Lawrence,

breeding grounds of Univ. of Kansas, in 1917, idem (Hb. Field 477327;

burs from lineal descendants of type material).

In 1915, Shull (loc. tit.), writing upon the physiological isolation of

types in Xanthium, described this species. Unfortunately, however,

no Latin diagnosis was published (as required by Article 36 of the

International Rules of Nomenclature, adopted at Vienna in 1905),

and so the name X. globosum must be regarded as having been hereto-

fore unbinding and based upon a foundation very insecure. Early in

1918 we took the liberty of writing to Dr. Shull regarding the

proper publication of a complete taxonomic description in Latin. Dr.

Shull promptly replied in a most cordial manner and very generously

placed at our disposal, for publication, not only descriptive notes and

photographs, but a sheet of the original type material, also other sheets

bearing lineal descendants of the type material etc. We have thought

it best to draw up our description rather closely from these sheets,

hence a somewhat narrower description has been presented than would

have been the case had we included the variations observed in the

Missouri specimens.

A study of ShulFs several specimens shows a high degree of uni-

formity among the fruits. The species is probably nearest to X. chinense

Mill., with which it perhaps intergrades, or hydridizes at times if left

to itself. We have seen specimens from Maryland and from Iowa

(G. H. Shull 392, along shore of Chesapeake Bay, south of Havre de

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 25

Grace, Maryland, 2 sheets in Hb. Gray; Hb. Mo. 85399; A. S. Hitch-

cock, Iowa City, Iowa, without date, Hb. Mo. 85406) which, while

referable to X. chinense, showed a strong approach, in the subglobose

character of the fruits, to X. globosum.

6. XANTHIUM ARCUATUM Millspaugh and Sherff, Field Mus. Bot. 4: 4.

PI. 2. 1918.

Caulis superne scabridus, 3-5 dm. altus. Folia deltoideo-ovata

3~5-lobata, dentata, basi cordata aut subtruncata, utrinque setulis

adpressis scabra, petiolis adjectis circ. i dm. longa, petiolis laminis

subaequantibus. Fructuum (PL VII., f. 6; PI. VIII., ff. 24-26) corpus

anguste ovatum, aculeis numerosis armatum, glandulis multis vestitum,

demum 1.3-1.5 cm. longum et 5-6 mm. crassum; rostris rectis aut

minime arcuatis, apice hamosis, non pubescentibus sed infra glandu-

los ferentibus, 3.5-5 mm. longis; aculeis tenuibus, maximam partem

arcuatis, plus minusve rubro-purpureo tinctis, apice hamosis, infra

glandulosis, 4-6 mm. longis.

DISTRIBUTION: New York.

SPECIMENS EXAMINED: NEW YORK: Chemung County, river shores

and low places, Oct. n, 1896, T. F. Lucy (Hb. Field 4953, type).

A species with burs intermediate between those of X. chinense and

those of X. pennsylvanicum, but having prickles more arcuate. Our

failure to find, in various herbaria, additional material matching the

type would seem to indicate that either X. arcuatum is a very rare

species or that it will subsequently prove to be of hybrid origin.

7. Xanthium curvescens sp. nov. PI. XI.

Caulis ramosus, rubens, scaber, +3 dm. altus. Folia deltoideo-

cordata, infirme trilobata, margine dentata, scabrida, minute reticulata,

punctis glandulosis numerosis minimis punctata, setulis minutis adpres-

sis scabra, non crassa, petiolis adjectis +i dm. longa, petiolis laminas

subaequantibus. Fructuum (PI. VII., f. 7; PI. VIII., ff. 27-29) corpus

anguste cylindrico-fusiforme, rubro-badium, superne sensim angus-

tatum et in duo rostra distantia productum, exteriore facie 30-50

aculeis armatum, glabratum sed glandulis minutis numerosis punctatum

uti bases aculeorumet rostrorum; rostris et aculeis rectis solum inferne,

superne valde arcuato-uncinatis; rostris crassioribus et passim paulo

longioribus, inferne breviter hispidis; fructus corpore demum 1.3-1.6

cm. longo et 3.5-5 mm. crasso; aculeis 3-6 mm., maximam partem

4.5-5.5 mm. longis.

DISTRIBUTION : Vermont.

SPECIMENS EXAMINED: VERMONT: Orwell, Willard W. Eggleston

1420 (type in Hb. Gray).

Because of its strongly bent prickles and beaks, we were disposed at

first to regard this species as a form of the European X. orientale L.

But in the many fruiting specimens of X. orientale examined from

26 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

Europe, we have found the fruiting involucres to be not only consider-

ably larger, but brownish rather than reddish, also much more pubescent

and the prickles nearly always more numerous. In its narrow, reddish,

remotely aculeate fruits, this species suggests the next, X. leptocarpum,

the type of which was collected likewise in western Vermont, about

three years earlier. Indeed, as a species, it seems to lie just half-way

between X. orientate and X. leptocarpum, and for a time we suspected

it of being a hybrid between these two species. But the apparent

absence of true X. orientale from all of North America1 would seem to

1 X. orientale L. Sp. PI. Edit. II, 2: 1400 (ex descript. et synon.; excl. loc.) 1763;

L. fil. Dec. II, PI. Rar. Hort. Upsal. tab. 17. 1763; Gaertner, Fruct. etSem. PI. 2:

tab. 164, f. 2. 1791; O. Hoffmann, Engler and Prantl Naturl. Pflanzenfamilien 4T:

223, f. 112. 1889; X. elatius & majus Americanum etc., Morison PI. Hist. Univ.

Oxon. 604, sect. 15, tab. 2, f. 2. 1699; X. majus canadense Hermann, Hort. Lugd.-

Batav. 635. 1687 (fide Thellung); Lappa canadensis minori etc., Ray, Hist. PL i:

165. 1686 (fide Thellung); X. canadense Miller, Gard. Diet. Edit. VIII, no. 2. 1768

(cf. Thellung, Verhandl. Bot. Verein Brandenb. 50°: 138. 1908; O. Hoffmann,

Engler and Prantl. Naturl. Pflanzenfamilien 4V: 223. 1889); X. cuneatum Moench,

Meth. Suppl. 300. 1802 (Moench gave an entirely inadequate description, —

"Xanthium, cuneatum, foliis cuneiformibus subtrilobis." He cited, however,

"Xanthium orientale Linnaei" and "Xanthium majus Americanum fructu spinulis

aduncis armato. Morison hist. III. p. 604, icon. Sect. 15 t. 2. f. 2 " for his two syno-

nyms); X. echinatum Wallroth, Monogr. Xanthium in Beitr. Bot. in: 239. 1844

(Walpers Repert. Bot. Syst. 6: 152. 1846) non Murray; X. macrocarpum DC., Fl.

Franc. Suppl. 356. 1815.

At various times in the past, Xanthium orientale L. has been reported as occurring

in America. Thus, as late as 1913, Britton and Brown (Illustr. Fl. Edit. II, 3: 346)

stated that this species was "naturalized in the West Indies." But an examination

of various specimens of Xanthium from the West Indies (among them a number from

the Herbarium of the New York Botanical Garden, and determined as X. orientale

L., evidently by Dr. Britton himself), fails to reveal to us a single specimen of X.

orientale. Indeed, all so-called specimens of X. orientale from the West Indies

that we have seen are referable to X. chinense Miller and differ very markedly

from X. orientale L.

Great confusion has existed heretofore among many botanists as regards the

application of the name X. orientale. Linnaeus himself prefaced his original descrip-

tion with three synonyms ("Xanthium elatius majus americanum, fructu spinulis

aduncis munito. Moris, hist. 3. p. 604. s. 15. t. 2. f. 2. Xanthium majus canadense.

Herm. lugdb. 635. Lappa canadensis minori congener sed procerior. Raj. hist. 165 ")

and with the statement, "Habitat in China, Japonia, Zeylonia."

If, on the one hand, we consistently follow the custom of taking earliest cited

synonyms with which to establish our concept of the species, there can arise practi-

cally no doubt. To be sure, Morison's figure has most of the prickles drawn arcuate

or even doubly bent, as in European plants of X. macrocarpum DC., while his

American material must surely have been another species (the Jamaica plants, for

example, undoubtedly belonging to X. chinense Miller). However, Morison definitely

cited the Lappa Canadensis material of the Royal Garden of Paris as a

basis for his species ("2. Elatius & majus Americanum, fructu spinulis aduncis

armato. Lappa Canadensis minori congener sed procerior, Hort. Reg. Par. E Vir-

ginia, Carolina & Jamaicensi Insula accepimus. V. icon., tab. aen. 2."). And (cf.

Thellung, Verhandl. Bot. Verein Brandenb. 50": 138. 1908) this cited material of

the Paris Garden was X. macrocarpum DC., for in the very year following the

publication of Morison's work, Tournefort (Instit. 1 : 439; 3: tab. 252, f. M. 1700)

cited and illustrated this "Lappa canadensis " material and his illus-

tration is positively of the X. macrocarpum DC. Thus, by taking in turn the earliest

cited synonym given by Linnaeus and by Morison, we find X. orientale L. to be the

plant later named X. macrocarpum DC. Thellung (loc. cit.) has come to the same

conclusion and he cites, furthermore, very strong evidence to show that the syno-

nyms of Hermann and Ray likewise belong with the true X. macrocarpum DC., i.e.,

DC. FL Franc., loc. cit. Later, De Candolle (Prodr. 5: 523. 1836) unfortunately

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 37

make an assumption to this effect purely gratuitous. Nor do we feel

inclined to regard our plant as an anomalous race or variety of X.

leptocarpum, since the arcuate character of its prickles is a character

that holds with a high degree of uniformity throughout the specimens

of the corresponding X. orientale of Europe.1

admitted other, specifically different material to his X. macrocarpum and so it is

highly important that, for a correct concept of the species, recourse be had only

to his original treatment in the Flore Francaise. The true X. macrocarpum DC. is

a plant with strongly hooked beaks and the prickles somewhat subremote, stoutish,

tending to be not only hooked at the apex, but also arcuate, often backwardly then

forwardly, from about the middle upward.

On the other hand, there is good reason for discarding the Linnaean synonyms

entirely, since Linnaeus himself advanced them in an interrogative way. Thus, at

the close of his description, he asked the question, "Synonyma americanae plantae

an differant? " Clearly, Linnaeus did not establish his species upon certain synonyms

and then doubtfully refer the plant under observation to it; but he did base his

species upon the plant material studied, drawing up a (for that period) good descrip-

tion of it, and then to this species the interrogative mark and the wording of the

question show that he doubtfully referred the early synonyms. (This point is indeed

important, for in case a discrepancy did exist between the synonyms and the plant

of the description, it is evident that Linnaeus definitely advanced the description

and not the synonomy. But, fortunately, no such discrepancy appears to have

existed.) — Linnaeus' doubts were evidently inspired by the fact that the cited

references, although agreeing with his plant, all had been regarded as pertaining to

American material. If we note his own citation of habitat, we find that he regarded

his Xanthium orientale as belonging to China, Japan and Ceylon. But, it happens

that his description is illuminated by a good, clear illustration published the same

year (1763) by his son, from plants at the Garden of Upsala. This illustration is

very decisive. It shows the Linnaean plant material of X. orientale to have been a

European plant (X. macrocarpum DC.), a plant that we have never known to come

from the Orient.

In 1815, De Candolle (loc. cit.) created the name Xanthium macrocarpum as a

straight synonym for the Linnaean description of Xanthium orientale and for the

illustration by Linnaeus' son. He was impelled to create the new name X. macro-

carpum because the species had not been proved to grow in the Orient and because,

even if it had, the name orientale would be hardly appropriate, since the plant had

been collected in Languedoc: " La description de Linni, la description et la figure de

Linne" fils se rapportent parfaitement a notre plante; malgre" cela j'ai cru convenable

de ne pas lui conseryer le nom d' orientale, i°. parce qu'il n'est pas prouv6 que cette

plante croisse en Chine, au Japon, a Ceylan; 2 . parce que cette habitation supposed

certaine, le nom d'orientale ne serait gu£re convenable, I'espSce se trouvant en

Languedoc. OElle a e'tte' trouve'e dans les vignes du bas Languedoc, par mademoiselle

Lucie Dunal." (Among various authentic French specimens of this species we have

seen an old one from De Candolle himself, collected in this same region, at Mont-

pelier. It is in the Torrey Herbarium, now at the Herbarium of the New York

Botanical Garden.)

De Candolle's procedure in seeking to supplant the name X. orientale with the

name X. macrocarpum would not, of course, be sanctioned by the Vienna Code

(Internat. Rules Bot. Nomencl., art. 50. 1906), and clearly the name X. orientale L.

must be retained.

Our search through botanical literature fails to show any true X. orientale to

have been collected in North America during recent times (Cf. Thellung. loc. cit. 141 :

"Indessen ist das echte X. orientale aus Nord-Amerika, wenigstens in neurerer Zeit,

nicht mit Sicherheit bekannt geworden.")

1 On the eve of publication, we have received an admirable set of specimens

collected for us by Mrs. Nellie F. Flynn at Burlington, Vermont. The set includes

Xanthium chinense, X. speciosum, X. italicum, X. leptocarpum and X. curvescens.

We have deposited the material of X. curvescens in Hb. Field, nos. 481623, 481624,

481625, 481626, 481627, 481630; Hb. Gray ;Hb. N.Y. Its burs show a curious simula-

tion of those of X. orientale L., but are much smaller. It was found growing with X.

italicum and X. leptocarpum. This fact naturally leads to the inquiry as to whether

or not X. curvescens may ultimately prove to be of hybrid origin.

28 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

8. XANTHIUM LEPTOCARPUM Millspaugh and Sherff, Field Mus. Bot.

4: 3, PL I. 1918.

Caulis superne scaber, 3-5 dm. altus. Folia plus minusve deltoidea

et trilobata, dentata, basi cordata aut subtruncata, utrinque setulis

adpressis scabrida, petiolis adjectis 7-19 cm. longa, petiolis laminis

subaequantibus. Fructuum (PI. VII, f. 8; PL VIII, ff. 30-32) corpus

anguste cylindrico-fusiforme, badium, superne sensim angustatum;

exteriore facie et basibus aculeorum et rostrorum pubescentibus,

glandulosis; 18-40 aculeis remotis, 2-3 aut rare -4 mm. longis; rostris

distantibus, arcuatis; rostris et aculeis ad apicem hamosis, rostris

crassioribus et paulo longioribus; fructus corpore 1.3-1.6 cm. longo,

3.5-5 mm. crasso.

DISTRIBUTION : Vermont.

SPECIMENS EXAMINED: VERMONT: Burlington, Sept. 12, 1896, L.R.

Jones (Hb. Field 430860, type); Shores of Lake Champlain, Oct. 30,

1895, and Sept. 8, 1896, Ezra Brainerd (Hb. Gray).

This species appears most closely allied with X. Wootoni Cockll.

Careful comparisons, however, of the type and supplementary material

with authentic specimens (cited below) of X. Wootoni do not permit us

to equate the two species. The burs of X. leptocarpum are uniformly

much narrower; moreover, they have about twice as many prickles as

do those of X. Wootoni and their beaks show no tendency to be more or

less cleft.1

9. XANTHIUM WOOTONI Cockerell ex De Vries, Sp. and Var. 140. 1905 ;*

cf. Proc. Biol. Soc. Wash. 16: 187. 1903.

X. commune var. Wootoni Cockerell, ibid., p. 9. 1903.

X. Wootoni Auct. ex Index Kew. Suppl. 3: 191. 1908.

X. oligacanihum Piper, Contrib. U. S. Nat. Herb, n: 551.

Caulis erectus aut sese extendens, sparsim scabrido-hispidus, 3-6 dm.

altus. Folia reniformi-orbiculata aut deltoideo-cordata, obscure lobata,

crenato-dentata, setulis minutis adpressis scabrida, petiolis adjectis

0.8-1.5 dm. longa, petiolis laminas aequantibus aut paulo excedentibus.

Fructuum (PL VII, f. 9; PL VIII, ff. 33-36) corpus oblongum, vel

stramineum vel badium vel etiam rubro-fuscum, superne sensim angus-

1 See also footnote (p. 27) under X. curvescens.

2 See also Science, New Series, 42: 871. 1915.

1 We have purposely given the synonomy as fully as we can. Cockerell originally

proposed the plant as a variety. But, in accordance with their entirely unjustified

method of indexing varieties, subspecies etc., as species, the Biological Society of

Washington indexed the plant at the back of their volume as a species. In 1905,

De Vries (loc. cit.) first stated the binomial at all creditably and he definitely attrib-

uted the name to Cockerell. As the retention of a multitude of taxonpmic binomials,

each accredited merely to some anonymous author (e.g., "Auct." in Index Kew.

loc. cit.) can result only in endless confusion in the future, we feel ourselves in accord

with the spirit of the Vienna Code (Internat. Rules Bot. Nomencl., art. 4: 2. 1906)

in taking De Vries' book as the place of valid publication.

APRIL, 1919. XANTHIUM — MILLSPATJGH AND SHERFF. 29

tatum et in duo (aut rarius tria) rostra distantia productum, 12-30

aculeis (3.5-6 mm. longis) armatum, molliter glanduloso-pubescens uti

bases aculeorum et rostrorum, 1.1-1.4 (rariter 1.6) cm. longum et 5-6

(-7, fide Piperi) mm. crassum; rostris rectis aut versus apicem incurva-

tis, saepe hiantibus et achaenia in conspectu ponentibus, aculeos

aequantibus; aculeis rectis aut subrectis sed ad apicem hamosis, non

pubescentibus nisi versus basim.

DISTRIBUTION : Massachusetts, New Mexico and Washington.

SPECIMENS EXAMINED: MASSACHUSETTS: South Boston, made land,

Oct. 4, 1909, Walter Deane (2 sheets, Hb. Gray). NEW MEXICO: Las

Vegas, T. D. A. Cockerell 15 (author's material of X. commune Wootoni

Cockerell, Hb. N. Y.); Las Vegas, in 1902, idem (author's material of

X. commune Wootoni Cockerell, Hb. Gray). WASHINGTON: Waits-

burg, bars of streams, Robt. M. Homer B. 272 (Hb. Gray) ; Bolles, in

fields, Sept. 18, 1893, C. V. Piper (Hb. N. Y.; cotype of X. oligacanihum

Piper).

Repeated studies upon this species have indicated it to be distinct

and worthy of specific rank. DeVries (loc, tit.} found that the seed sent

him by Cockerell (who was the first to pay particular attention to the

plant) produced, when planted in DeVries' garden, plants true to type.

Wooton and Standley (Contrib. U. S. Nat. Herb. 19: 635. 1915),

while reluctantly retaining the form as a variety of Xanihium commune

Britton (=X. italicum Moretti), state nevertheless that it "seems

distinct enough from X. commune to be regarded as a species. It cer-

tainly is more easily separable from that than are most of the eastern

species from each other. ..... Ordinarily the two plants are distinct

enough." Cockerell himself (Science, New Ser. 42: 871. 1915),

although at first inclined to regard the plant as a variety, finally, as a

result of an additional observation upon X. commune and also in view

of DeVries' results, stated, "We must apparently conclude that X.

Wootoni is a valid species, but that commune from time to time varies

or mutates to a virtually identical form." And, several years before,

Piper regarded it as a species. He stated that it differed "from any

other American species in the small size of the fruit and the relatively

few prickles" (Piper, loc. tit.}. But, as he was dealing with specimens

from Washington, he apparently overlooked the literature dealing with

X. Wootoni, which had been known only from New Mexico; — hence

the reason for his name X. oligacanihum.

We have studied several authentic specimens from New Mexico and

from Washington. There is no essential difference to be found between

the two sets of specimens. Those from Washington have burs more

brownish in color (rather than whitish to straw-colored) and the prickles

are very slightly stouter. But both have the beaks of the burs tending

30 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

to be strongly cleft or 2-valved (sometimes more or less malformed),1

and in various other characters are too close to admit of any taxonomic

separation.

The specimens collected by Deane in Massachusetts have the nu-

merous burs identical with those on Piper's plant from Washington,

but the leaves differ noticeably in being sharply lobed and dentate.

Our knowledge of the genus, however, convinces us that the foliage

characters are entirely too unstable to warrant satisfactory segregation

of forms when unaccompanied by definite characters of the fruits.

Hence we must refer the Massachusetts plants to this species.

10. Xanthium cenchroides, sp. nov.

Caulis longitudinaliter plus minusve purpureo-maculatus, supra

subscabridus. Folia non crassa, dentata, supra scabrida, infra scabra et

minute reticulata. Fructus (PI. VII, f. 10; PL VIII, ff. 37-39) ovati,

superne in duo rostra producti; exteriore facie glanduloso-hispida et

circum 25 aculeis armata; corpore (rostris non adjectis) 1.5-1.7 cm.

longo et 6-7 mm. lato; rostris arcuatis, infra hispidis, supra glabratis

et ad apicem hamosis, circum 8 mm. longis; aculeis rectis aut subrectis,

infra hispidis, supra glabris et ad apicem hamosis, 8-10 mm. longis.

DISTRIBUTION : Texas.

SPECIMENS EXAMINED: TEXAS: near Ferris, J. Reverchon 2332

(type in Hb. Mo. 85563; additional material, ibid., on sheet no. 85564).

The type material is very fragmentary, the leaves nearly all having

been destroyed by worms. The fruiting burs, however, are present in

fair quantity and are very distinct from those of any other Xanthium

known to us. In their small number of prickles, the burs resemble those

of X. Wootoni Cockll., but in size of body, length of prickles etc., there

are very pronounced differences. The burs suggest very strongly the

fruiting involucres of Cenchrus carolinianus Walt., although of course

much larger.

11. XANTHIUM INFLEXUM Mack, and Bush, Rept. Missouri Bot. Gard.

16: 106. 1905.

Caulis glabratus aut superne setulis albis plus minusve scabridus,

ramosus, 1—1.5 m. altus. Folia cordata aut ovato-cordata, tri-aut sub-

quinquelobata, irregulariter serrata aut dentata, infirme aut valide

scabrida, petiolis adjectis 0.8-2.5 dm. longa, petiolis laminis subaequan-

tibus. Fructuum (PL VII, f. n; PL IX, ff. 1-4) corpus oblongo-ellip-

ticum aut ovato-oblongum, exteriore facie non paucis aculeis armatum,

aliter glabrum aut sparsim glandulosum, 1.3-1.7 (-2) cm. longum et

6-7.5 rnm. crassum; rostris validis, maturis ad medium abrupte flexis,

valde incurvatis, ad apicem hamosis, saepe mutuo contingentibus, infra

1 The specimen collected by Piper has several burs with the achenes protruding

at the top.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 31

glanduloso-pubescentibus, plerumque 5-7 mm. longis (auctores "circ.

10 mm. longis" dixerunt inaccurate); aculeis tenuibus, subconfertis,

plerumque arcuatis, ad apicem hamosis, infra glanduloso-pubescentibus

aut demum glabratis, 4.5-6.5 mm. longis, saepequibusdamabnormalibus

versus rostra longissimis (8-10 mm.).

DISTRIBUTION: Southwestern Illinois to Arkansas.

SPECIMENS EXAMINED: MASSACHUSETTS: Cambridge, Botanical

Garden, Oct., 1848, from seed collected by Engelmann (presumably

collected the preceding year at East St. Louis, Illinois) Asa Gray (two

sheets in Hb. Gray, bearing nos. 172, 1720 and 174). ILLINOIS: East

St. Louis, river bank, Sept., 1847, George Engelmann (Hb. Mo. 85551);

MISSOURI: Courtney, in bottoms, B. F. Busk 869 (Hb. Gray; Hb. Mo.

85519; an atypic form apparently hybridized with X. pennsylvanicum

Wallr.) ; Courtney, in bottoms, idem 1804 and 1805 (Hb. Mo. 85409 and

85531 respectively); Courtney, in bottoms, idem 1806 (Hb. Mo. 85522;

Hb. Gray) ; Courtney, in bottoms, idem 1916 (Hb. Mo. 85520 and 85521 ;

Hb. Gray; — type material). ARKANSAS: Fulton, along river, B. F.

Bush 1026 (Hb. Mo. 85554 and 85555; Hb. Gray; — a form approaching

X. pennsylvanicum Wallr., the burs having long, somewhat delicate

beaks, which are not decidedly inflexed).

Fortunately, we have been able to examine fairly numerous speci-

mens of this little known species. The burs have a body averaging of

larger size than in X. chinense Mill. ; in shape and appearance the body

is intermediate between that in X. chinense Mill, and that in X. penn-

sylvanicum Wallr. The prickles are long, as in X. speciosum Kearney,

but more slender, much smoother and somewhat less abundant.

12. X. PENNSYLVANICUM Wallr.1 Beitr. Bot. in: 236. 1844.; Britton

and Brown Illustr. Fl., Edit. II, 3: 346, f. 4137. 1913.

X. pennsylvanicum vars. glandulosum and eglandulosum Wallr.

loc. cit.

X. saccharatum Wallr. loc. cit. 238;

X. affine Greene, Pittonia 4: 60. 1899.

X. californicum Greene and X. acutum Greene, loc. cit. 62.

Caulis subtenuis scabridus, aut infra levis, 3-9 dm. altus. Folia

deltoideo-ovata aut cordata, dentata, saepe acute 3~5-lobata, utrinque

setulis minutis adpressis scabra, petiolis adjectis 0.7-2 dm. longa, petiolis

laminas subaequantibus aut excedentibus. Fructuum (PI. VII, f. 12;

PI. IX, ff. 5-10) corpus nunc anguste cylindricum, nunc oblongum,

nunc ovato-fusiforme, nunc etiam ovoideum, sed plerumque plus

minusve cylindricum, glabrum aut glabratum aut pilis glandulosis

brevibus vestitum, 1-2 cm. longum et 5-8 mm. crassum, aculeis arma-

tum; rostris tenuibus aut crassis, infra glanduloso-pubescentibus, versus

1 The name as originally given by Wallroth was spelled X. pensylvanicum.

Fernald (Rhodora 19: 70. 1917) is inclined to retain the old spelling in such cases

and gives the historical reasons for pursuing such a course.

32 FIELD MUSEUM OP NATURAL HISTORY — BOTANY, VOL. IV.

apicem glabris et saepius incurvatis, ad apicem hamosis, 4-6 mm.

longis; aculeis subremotis et subvalidis (aut rarius confertis et tenuibus),

versus basim glandulosis et saepe sparsim pubescentibus, aliter glabris,

ad apicem hamosis, interdum purpureo-tinctis, 3-7 mm. longis.

DISTRIBUTION : Massachusetts, Ontario and Washington to Florida,

Texas and California; perhaps also in Mexico; frequent in the Hawaiian

Islands. \

SPECIMENS EXAMINED (partial list):1 MASSACHUSETTS: Boston, Sept.

13, 1895, Emile F. Williams (Hb. Gray). RHODE ISLAND: Newport,

waste ground, Fernald and Long 10658 (Hb. Gray). PENNSYLVANIA:

without locality, invading the marshes ("in paludos"), Sept., 1824,

Poeppig (Hb. Mo. 85594; cotype of X. pennsylvanicum var. eglandulosum

Wallr.). MARYLAND: Plummer's Island, near Cabin John, T. H.

Kearney 221 (Hb. U. S. 640384); east shore of Maxwell's Point, above

tide, George H. Shull 332 (Hb. Gray) ; shore of Chesapeake Bay, south of

Havre de Grace, idem 390 (Hb. Gray; Hb. Mo. 85436). VIRGINIA:

Alexandria County, near Barcroft Station, Oct. 3, 1915, E. S. Steele

(Hb. U. S. 643281). FLORIDA: Hillsborough County, waste ground,

A. Fredholm 6426 (Hb. Gray). ONTARIO: near Sarnia, roadside ditches,

C. K. Dodge 49 (Hb. Gray). MICHIGAN: Port Huron, dryish ground in

streets, C. K. Dodge 47 (Hb. Gray). ILLINOIS: near French Village,

Sept. 6, 1892, H. Eggert (Hb. Mo. 85438); East St. Louis, Sept., 1847,

Dr. George Engelmann (Hb. Mo. 85452); Carthage, F. C. Gates 9996

(Hb. Field 472736); vicin. of Catlin, bank of creek, 0. E. Lansing, Jr.,

3532 (Hb. Field 346590); Urbana, open wet soil, Sept. 19, 1901, M. S.

Sheldon (Hb. Gray) ; Chicago, along walk, Earl E. Sherjj 3080 (Hb. Field

480737 and 480738); Hinsdale, waste ground, Ernest C. Smith 529,

(Hb. Field 127018). KENTUCKY: locality not stated, in 1842, Dr. C. W.

Short (Hb. Gray). IOWA: Decatur County, in fields, Aug. 29, 1897,

Fitzpatrick and Fitzpatrick (Hb. Gray); Ames, without date, A. S.

Hitchcock (Hb. Mo. 85450). MISSOURI: Courtney, in bottoms, B. F.

Bush 870 (Hb. Mo. 85539); Courtney, in bottoms, idem 1789 (Hb.

Gray); Courtney, in bottoms, idem 1790 (Hb. Mo. 85538); Courtney, in

bottoms, idem 1792 (Hb. Mo. 85530); Courtney, in bottoms, idem 1793

(Hb. Mo. 85542); Courtney, in bottoms, idem 1794 (Hb. Mo. 85529);

Courtney, in bottoms, idem 1802 (Hb. Gray; Hb. Mo. 85602) ; Courtney,

in bottoms, idem 1809 (Hb. Mo. 85541); Courtney, in bottoms, idem

1911 and 1914 (Hb. Mo. 85540 and 85533 respectively; probably hybrid-

ized with X. chinense Miller) ; Courtney, in bottoms, idem 1915 (Hb. Mo.

85537); St. Louis, Aug. 25, 1874, H. Eggert (Hb. Gray); St. Louis

County, West Webster, Dr. J. M. Greenman 3799 (Hb. Mo. 807756);

1 A large number of specimens omitted here from lack of space.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 33

Webb City, low ground, E. J. Palmer 767 (Hb. Mo. 756626) ; La Russell,

low ground, idem 1300 (Hb. Mo. 85456; fruit with bristly prickles and

approaching that of X. italicum Mor.). ARKANSAS: Fulton, along river,

B. F. Bush 1027 and 1028 (Hb. Mo. 85423 and 85543 respectively).

NORTH DAKOTA: Leeds, waste places, Aug. 21, 1902, Dr. J. Lunell

(Hb.Gray). NEBRASKA: Red Cloud, Rev. J.M. Bates 4745 (Hb. Gray).

KANSAS: Manhattan, Sept. 20, 1887, W. A. Kellerman (Hb. Mo. 85449);

Riley County, low ground, /. B. Norton 261 (Hb. Mo. 85448). OKLA-

HOMA: Sapulpa, B. F. Bush 299 (Hb. Mo. 85544); vicin. Ottawa, low

waste place, G. W. Stevens 2568 (Hb. Gray). TEXAS : Columbia, in sand,

B. F. Bush 1344 (Hb. Mo. 85467); Dallas, in wastes, /. Reverchon 2589

(Hb. Mo. 85480, 85481 and 85546). COLORADO: Naturita, moist ditch

bank, Ernest P. Walker 545 (Hb. Gray; Hb. U. S. 544637). NEVADA:

Washoe County, Truckee Pass, Sept. 15, 1909, A. A. Heller (Hb. Calif.

196027; a form with burs precisely like those on type of X. acutum

Greene at Hb. Greene, except slightly pubescent). IDAHO: New

Plymouth, waste ground, /. Francis Macbride 718 (Hb. Gray, having

burs almost exactly identical with those on type of X. acutum Greene,

in Hb. Greene; a rather immature specimen is also in Hb. Mo. 85515).

UTAH: Vermilion, Marcus E. Jones 5842 (Hb. Mo. 85490 and 85492);

Peterson, Peterson Canyon, Pammel and Blackwood 3888 (two sheets in

Hb. Gray); road between Monticello and Bluffs, Rydberg and Garrett

9872 (Hb. U. S. 765345). ARIZONA: Tucson,Valley of Santa Cruz River,

John J. Thornber 8 (Hb. Mo. 85496; Hb. Calif. 129897). WASHINGTON:

Waitsburg, bars of streams, Robt. M. Homer B 273 (Hb. Gray; this is not

X. varians Greene as erroneously stated by Piper, Contrib. U. S. Nat.

Hb. ii : 551. 1906) ; West Klickitat County, sandy banks of Columbia

River, W. N. Suksdorf 1584 (Hb. Field 89752 and 89753; Hb. Calif.

130204; Hb. Gray; Hb. Greene 19830; type and cotypes of X. affine

Greene). OREGON: Union County, Snake River, sand-bars, W. C.

Cusick 1000 (Hb. Gray); near Prineville, /. B. Leiberg 842 (Hb. Gray).

CALIFORNIA: Los Angeles County, near Soldiers' Home, Sept., 1905,

Dr. J. Q. Adams (Hb. Calif. 74043) ; San Diego County, vicin. Ramona,

Stockton Ranch, Oct., 1905, Katharine Brandegee (Hb. Calif. 168741;

burs identical with those on type and cotypes of X. affine Greene);

vicin. Ramona, Stockton Ranch, Oct., 1905, eadem (Hb. Calif. 168816;

a form with burs matching those on type of X. calif ornicum Greene in

Hb. Greene); vicin. Ramona, Stockton Ranch, Oct., eadem (Hb. Calif.

168813) ; vicin. Mendocino, H.E. Brown 938 (Hb. Mo. 85391 ; this is not

X. echinatum Murr., as erroneously stated by Thellung, Verhandl. Bot.

Verein Brandenb. 50°: 144. 1908); roadside near Yreka, George D.

Butler 527 (Hb. Calif. 164145); Escondido, Harley P. Chandler 5399

34 FIELD MUSEUM or NATURAL HISTORY — BOTANY, VOL. IV.

(Hb. N. Y.) ; Temescal, Oct., 1889, Edward L. Greene (Hb. Greene 19822 ;

Greene's only specimen of his X. californicum and by us regarded as

the type; matched most minutely by W. L. Jepson's plant from Oak-

land,— see below) ; Amador County, Middle Fork, George Hansen 700

(Hb. Mo. 85389) ; Suisun Marsh, along railroad near Suisun, A. A. Heller

7550 (Hb. Gray; Hb. Mo. 85386; Hb. N. Y.); cultivated land, north of

Oroville, idem 12647 (Hb. Field 460600; Hb. Mo. 802978; atypical and

approaching X. italicum Mor.) ; Rio Vista, bank of Sacramento River,

Sept. 16, 1891, W. L. Jepson (Hb. Calif. 36799; this is a form interme-

diate between the types of X. acutum Greene and X. californicum

Greene, in Hb. Greene); Oakland, Oct. i, 1894, idem (Hb. Mo. 85387;

the exact form described by Greene as X. californicum and important

as coming from the range emphasized by him, "Middle California,

especially about San Francisco Bay"); near San Francisco, in 1866,

Dr. A. Kellogg (Hb. Gray); near Stockton, in 1888, J. A. Sanford (Hb.

Greene 19819; type of X. acutum Greene).

Wallroth divided this species into two varieties, o. glandulosum and

ft. eglandulosum, according to the presence or absence of minute glands

upon the fruits and lower surfaces of the leaves. The var. glandulosum

was collected by Beyrich at Asheville [North Carolina] in 1833, while the

var. eglandulosum was collected by Poeppig in Pennsylvania, Sept., 1824.

We have not seen type material of var. glandulosum; of var. eglandu-

losum, however, we have seen the cotype specimen in the Bernhardi

Herbarium (Hb. Mo. 85594). But this shows clearly, under a lens with

a magnification of fourteen diameters, many minute glands, — evidently

missing on the type or perhaps overlooked by Wallroth. Thus Wall-

roth's separation of the species into two varieties is seen to be without

real basis in fact.

Among botanists there has been almost endless confusion between

X. pennsylvanicum and the species treated below as true X. italicum

Mor. Our own experience in the herbarium indicates these to be, with-

out question, distinct. In the field, our numerous observations during

the season of 1918 show that, where the two grow side by side, X.

italicum commonly displays a more compact mass of burs near the apex

of the stem and branches than does X. pennsylvanicum. This com-

pactness, added to the greater pubescence of the burs, often imparts to

X. italicum an appearance very unique.

Of X. saccharatum Wallr., there is the cotype in Gray Herbarium.

This is plainly X. pennsylvanicum. We find a badly scrawled name

given for the locality to say "Bexar." Clearly the plant (Berlandier

1865} was collected at Bexar, Texas, and not in Mexico as some writers

have persisted in stating (although, to be sure, Texas had been a part

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 35

of Mexico until shortly before Wallroth's publication of the name X.

saccharatum) . l

Of X. affine Greene, X. californicum Greene2 and X. acutum Greene,

we have seen the types (all in Hb. Greene); of X. affine we have seen

also various cotypes. So different do these forms appear at first that one

might well mistake them as typifying three distinct species. However,

the large number of herbarium specimens that we have examined from

the Pacific Coast show that specific segregation is entirely impossible.

So polymorphous does X. pennsylvanicum become in its western range

that, in California alone, as many as six or seven forms may be found.

In the eastern part of the United States, X. pennsylvanicum displays

much less variation, both in fruits and in general habit.

13. Xanthium calvum sp. nov. PI. XII.

Caulis erectus, rubescens, saepe maculis purpureis parvis longitu-

dinalibus punctatus, subscabridus aut infra etiam glaber, circ. 4-9 dm.

altus. Folia ovato-cordata aut ovato-triangulata, ad basim vel orbicu-

lata vel truncata vel cordata, plerumque atro-viridiora, crenato-dentata,

saepe dentato-lobata, setulis minutis adpressis scabrida, petiolis adjectis

0.6-2 dm. longis, petiolis laminis subaequantibus. Fructus (PI. VII,

f. 13; PI. IX, ff. 11-12) pauci aut numerosi, corpore crasso ovato-

fusiformi fusco, utrinque subacuto, exteriore facie breviter et minime

pubescenti, glanduloso, aculeis subremotis armato, 1.5-1.8 cm. longo,

circum 8 mm. crasso; rostris infra crassis et validis, ad basim glanduloso-

pubescentibus, ad medium plerumque inflexis, ad apicem plus minusve

hamosis, 3-5 mm. longis; aculeis rectis, ad basim glandulosis aut ranter

pubescentibus, aliter glabris, ad apicem hamosis, 4-6 mm. longis;

rostris et aculeis plerumque purpureo-tinctis, praesertim versus apicem.

DISTRIBUTION: California.

SPECIMENS EXAMINED: CALIFORNIA: vicin. of Palo Alto, foothills,

C. F. Baker 1760 (Hb. Calif. 131236, type; Hb. Field 226601; Hb. Gray;

Hb. Mo. 85385; Hb. N. Y.); Neponset, Salinas River, L. R. Abrams

4023 (Hb. Calif. 149139); West Berkeley, Harriet A. Walker 478 (Hb.

Calif. 130051).

1 It may be remarked that the type of X. crassifolium Millsp. and Sherff (Field

Mus. Bot. 4: 5. 1918) was collected at San Antonio, not far from Bexar, in Bexar

County, Texas. The two plants show a close resemblance, but the Berlandier plant

is much thinner-leaved and less scabrous. We are disposed to consider X. crassifolium

as probably a variety or race of X. pennsylvanicum, — a conclusion that we have

reached also in the case of X. acutilobum Millsp. & Sherff (he. cit., p. 6). Since de-

scribing X. crassifolium (Field Mus. Bot. 4:4. 1918) we have found several somewhat

intermediate herbarium specimens. One of these, C. L. Shear 220, vicin. of Osborne

City, Kansas, Aug. 27, 1894 (Hb. Gray), has the coarse, highly scabrous stem and

leaves of X. crasstfolium, but the leaves are large, as in X. pennsylvanicum.

JAt various times in later years, Dr. Greene erroneously determined certain

specimens of Xanthium as representing his X. californicum. These belonged to

X. pennsylvanicum, X. calvum, etc. Greene's own type specimen of X. califor-

nicum was, as stated above, the same form as that collected by W. L. Jepson, Oak-

land, California, Oct. i, 1894 (Hb. Mo. 85387), a form of X. pennsylvanicum.

36 FIELD MUSEUM or NATURAL HISTORY — BOTANY, VOL. IV.

A species with very unique aspect of foliage as well as of fruit. Speci-

mens of the type collection had been determined by E. L. Greene as

X. calijornicum Greene (cf. p. 35, footnote 2). But a study of Greene's

type of X. californicum shows no approach in fruit characters to the

type of X. calvum. We have seen several sheets of X. pennsylvanicum

having fruits typical of that species but with foliage offering a perplexing

resemblance to that of X. calvum (e.g., C. F. Baker 1512, along borders

of marshes, Palo Alto, California, Hb. Gray; Harley P. Chandler 5399,

Escondido, California, Hb. Calif. 64835). Future investigation upon the

status of such forms, which are possibly hybrids, would seem highly

desirable.

The specific designation calvum is given in allusion to the bald or

smoothish appearance of the body and prickles of the mature fruit.

14. XANTHIUM PALUSTRE Greene, Pittonia 4: 63. 1899.

Caulis glaber aut paulo scabridus, interdum rubescens, saepe lineis

purpureis longitudinalibus maculatus, verisimiliter 0.5-1 m. altus.

Folia ovato-cordata aut deltoidea, dentata, plus minusve lobata, utrin-

que setulis minutis adpressis scabra, petiolis adjectis 0.8-3 dm. longa,

petiolis laminas subaequantibus aut excedentibus. Fructuum (PI. VII,

f. 14; PI. IX, ff. 13-15) corpus viridi-fuscum, demum crasso-oblongum

et nitens, glandulosum sed parce pubescens, circ. 1.8 cm. longum et

8—9 mm. crassum, aculeis brevibus armatum; rostris brevibus, crassis,

pubescentibus, supra incurvatis, ad apicem saepe subhamosis, 3-5 mm.

longis; aculeis numerosis sed vix confertis, versus basim crassum glandu-

losis et saepe sparsim pubescentibus, supra tenuibus et glabris, ad

apicem hamosis, 2-2.5 (ranter 3-3.5 aut etiam -4) mm. longis.

DISTRIBUTION : California.

SPECIMENS EXAMINED: CALIFORNIA: Suisun Marsh, in 1893, Edw.L.

Greene (Hb. Greene 19833 and 19834; type sheets); Lathrop, Harriet A.

Walker 926 (Hb. Calif. 201224); Suisun, eadem 973 (Hb. Calif. 128022).

In Greene's Herbarium are two specimens to represent this rare and

little known species, both of them collected by Greene himself at Suisun

Marsh, and which may properly be taken as the types of the species.

These have fruits just as described by Greene, except that they are more

nearly oblong than he implied and had best not be described as "slightly

obovate-oblong." Furthermore, they tend toward a greenish-brown in

color, with some of the prickles becoming reddish.

The first specimen by Miss Walker (listed above) is, in our opinion,

clearly X. palustre, but it shows an approach toward X. pennsylvanicum

Wallr. in having prickles 3-3.5 (a few even 4) mm. long. Miss Walker's

second specimen (no. 973), however, comes from the type locality and

matches the two type specimens identically, both as to foliage and as to

fruits.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 37

15. Xanthium australe sp. nov. PL XIII.

Caulis scabridus, plus minusve maculis purpureis parvis linearibus

punctatus, verisimiliter 0.5-1 m. altus. Folia petiolata, trinervia,

deltoideo-cordata, saepe obscure lobata, dentata, utrinque setulis minu-

tis adpressis vestita, petiolis adjectis 0.8-2 dm. longa, petiolis laminis

subaequantibus. Fructuum (PI. VII, f. 15; PL IX, ff. 16-18) corpus

ovoideo-subglobosum, subsparsim glanduloso-pubescens aut glabratum,

0.9-1.1 cm. longum et 6-7 mm. crassum (aut etiam 1.3-1.5 cm. longum

et 8-9 mm. crassum, in specimine chilensi), aculeis confertis armatum;

rostris attenuatis, rectis aut paulo inflexis, ad apicem subrectis aut

uncinatis, infra pubescentibus, 6-9 mm. longis; aculeis tenuibus, rectis

aut paulo arcuatis, infra nee dense nee longe pubescentibus (in specimine

chilensi quibusdam aculeis glandulosis et non pubescentibus), supra

glabris, ad apicem uncinatis, 4-5 mm. longis.

DISTRIBUTION: Mexico, Paraguay and Chile.

SPECIMENS EXAMINED: TAMAULIPAS: vicin. of La Barra, 8 km. east

of Tampico, at sea-level, Dr. Edward Palmer 275 (Hb. U. S. 463216,

type). PARAGUAY: Asuncion, Thomas M or ong 807 (Hb. N. Y.). CHILE:

Valparaiso, Dr. Mertens (ex Hb. Acad. Petrop., in Hb. Gray).

The long fruiting beaks of this species suggested to us at first an

affinity with the long-beaked West Indian form of X. chinense Mill.

(X. longirostre Wallr.). A consideration, however, of the other fruit

characters, as well as of foliage, shows no further relationships of a

specific nature.

There is a slight possibility that this is the species which Vellozo had

in mind when figuring his Xanthium brasilicum. But a careful inspec-

tion of Vellozo's plate (Fl. Flum. 10: tab. 23. 1827) shows it to be all

too crude and lacking in definite detail to permit of satisfactory inter-

pretation.1 Indeed, if the plate be at all accurate, it clearly represents

some other species, for the characters of the bur as there shown are not

those of X. australe.2

1 It is surprising to find that Baker (Martius Fl. Bras. 6ra: 147. 1884), notwith-

standing the crudity of this plate, actually made it the basis for a new combination

in nomenclature, X. strumarium L. var. brasilicum (Velloz.) Baker.

2 We have seen no authentic material of the inadequately described X. homo-

thalamum of Sprengel (Neue Entdeck. i: 259. 1820) from Brazil. We note that

the name X. homothalamum was entirely omitted by Baker from his treatment of

Brazilian Xanthia (Martius Fl. Bras. 6m: 147. 1884). Sprengel himself appears to

have seen only scanty material of the plant ("Licet haut perfecta huius plantae

exemplaria investigare potuerim," loc. cit., p. 260). He described the fruits briefly:

"In ambitu sex aut octo drupae oblongae sulcatae, aculeis flavis uncinatis armatae.

Singulae continent semen testa fusco-nigra obductum, in quo, sine albumine, embryo

rectus oblongis cotyledonibus mediocriter carnosis, sedet." We find nothing in his

description which might justify the reference of our X. australe to X. homothalamum.

38 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

1 6. XANTHIUM ECHINATUM Murr., Comm. Goetting. 6:32 and tab. 4.

1783-1784.

X. maculatum Raf., Amer. Journ. Sc. i: 151. iSig.1

Caulis scaber aut scabrido-hispidus, purpureo-maculatus, 3-6 dm.

altus. Folia setulis adpressis scabra, plerumque cordata et obtuse

lobata, obtuse et remote dentata aut serrata, petiolis adjectis 0.6-2.3

dm. longa, petiolis laminas subaequantibus aut excedentibus. Fructuum

(PI. VII, f. 16; PI. IX, ff. 19-21) corpus crasso-ovale aut rare sub-

globosum, glanduloso-hispidum et aculeis subremotis armatum, demum

1.6-2 cm. longum et 0.8-1 cm. crassum; rostris validis, incurvatis, ad

apicem saepius hamosis, infra hispidis, 3-5 mm. longis; aculeis tenuibus,

rectis aut arcuatis, ad basim (aut usque ad medium) hispidis, supra

calvis, ad apicem saepius hamosis, rostris subaequantibus.

DISTRIBUTION: Quebec to New Jersey, also (apparently adventive)

in Virginia, Ontario, North Dakota and Missouri.

SPECIMENS EXAMINED: QUEBEC: Longueuil, shores of St. Lawrence

River, Brother Victorin 1056 (Hb. Gray). ONTARIO: Ottawa, McKay

Lake, Aug. 3, 1911, John Macoun (Can. Geol. Surv. no. 87545 in Hb.

Mo., no. 719897). MAINE: Prouts Neck, Sept., 1898, Miss M. E. Blatch-

ford (Hb. Gray). NEW HAMPSHIRE: Newcastle, Little Harbor, Sept. 19,

1901, Entile F. Williams (Hb. Gray). MASSACHUSETTS: Boston, Savin

Hill, Aug. 28, 1853, William Boott (Hb. Gray); Cape Cod, Hyannis Port,

/. M. Greenman 361 (Hb. Mo. 722293); Pemberton, sandy beach, Aug.

27, 1897, B. L. Robinson (Hb. Gray); Nonquitt, Aug. 27, 1888, E. L.

Sturtevant (Hb. Mo. 85501); Nonquitt, along sea-shore, Sept. 25, 1888,

idem (Hb. Mo. 85500); Dartmouth, roadside, Sept. 27, 1889, idem (Hb.

Mo. 85502); Revere, seashore sands, Aug. 22, 1896, Emile F. Williams

(Hb. Gray); Craigville, sandy roadside, Sept. 5, 1898, idem (Hb. Gray);

Scituate, seashore, Oct. 29, 1899, idem (Hb. Gray); North Scituate,

Sept. 6, 1897, idem (Hb. Gray). RHODE ISLAND: Block Island, sandy

sea-beach, southwest of Chagum Pond, Fernald, Hunnewell 2nd and

Long 10659 (Hb. Gray); without locality, in 1848, Flint (Hb. Gray).

NEW YORK: Long Island, Rockaway Beach, Sept., 1892, Dr. Smith Ely

Jellife (Hb. Field 396974). NEW JERSEY: Ocean County, Tom's River,

sea-beaches, Kenneth K. Mackenzie 1046 (Hb. Mo. 85503). VIRGINIA:

Cape Charles City, Canby and Rose 845 (Hb. U. S. 297952; — an anomal-

ous form with burs glabrate but glandular upon the body, offering a

strong superficial resemblance to X. palustre Greene). MISSOURI:

Allenton, Sept. 20, 1890, George W. Letterman (Hb. Mo. 775049; — a

form with burs approaching those of X. italicum Mor.). NORTH DAK-

1 Torrey and Gray (Fl. N. Amer. 2: 295. 1843) described a variety of X.

echinatum Murr. ("j8. prickles of the oval-oblong fructiferous involucre stouter and

less crowded; leaves incisely lobed") from the "banks of Spirit Lake, head-waters of

the Little Sioux River of the Missouri, Mr. Nicolletl" We have seen no authentic

material of this variety.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERPF. 39

OTA: Leeds, fields, Aug. i6-Sept. 6, 1899, Dr. J. Lunell (Hb. Gray);

Leeds, along running water, Aug. 28, 1902, idem 82 (Hb. Gray).

This species was badly confused by Wallroth (Beitr. Bot. in: 239.

1844) with the true X. orientale L. Indeed, many other botanists have

fallen into similar errors, so that in literature we find X. echinatum

erroneously equated with a number of entirely distinct species. Thus,

for example, Thellung (Verhandl. Bot. Verein Brandenb. 50": 142-144.

1908) actually gives as synonyms, X. italicum Mor., X. pennsylvanicum

Wallr., X. riparium Lasch, X. campestre Greene1 and X. chinense Mill.

Murray's original description not only was very complete but was

accompanied by a good plate.2 This plate shows the fruiting involucres

to have an ovoid body, with short, rather remote prickles and very wide

achenes (ff. i, 7 and 8). Thellung (loc. tit.) attempts to differentiate

between Murray's description and plate, retaining the former and

excluding the latter. But Murray's description ("

Capsula ovalis, olivae magnitudinis, hirsuta, antice hamosa, hamis

inflexis hispidis, vestita aculeis uncinatis, divergentibus, consertis, sur-

sum et apice nudis, basi deorsum echinatis per setas rigidas albidas,

rectiores; bilocularis ") harmonizes perfectly, in our opin-

ion, with the plate. Moreover, Murray himself stated that his plant,

raised in 1783, came from fruits sent him by Von Wangenheim, from

New York. And it is precisely in the Atlantic coastal region beginning

with New York and extending north and south that almost all the

plants matching Murray's plate and description are found. Still fur-

ther, Murray's reference to an olive in describing the fruits ("Capsula

ovalis, olivae magnitudinis") is very significant. The plants cited in

our foregoing list as representing true X. echinatum, display, more than

any other native species of Xanthium from Eastern North America,

an open, plump, ovoid appearance to the body of the bur in such a way

as to suggest an olive.

Numerous authors, like Thellung, have confused X. echinatum with

the European X. riparium Lasch. All the European specimens of

X. riparium examined by us (about fifteen sheets) have shown burs

uniformly smaller, much narrower and with much smaller achenes.

It appears to us probable that no European botanist, after examining

several American specimens of X. echinatum, would hesitate to regard

X. riparium as distinct.

The plant described by Rafinesque (loc. tit.) as X. maculatum, came

1 Thellung had seen, for X. campestre.only an incorrectly determined specimen,

H. E. Brown 938.

a Cf. Torr. and Gray (Fl. N. Amer. 2: 295. 1843), who referred to this plate as

"a good figure." But Thellung (loc. «'/.), who clearly had a very incorrect con-

ception of Murray's species, called the plate very bad ("pessima").

40 FIELD MUSEUM or NATURAL HISTORY — BOTANY, VOL. IV.

likewise from "the neighbourhood of New York" ("on Long

Island, near the sea-shore and marshes"). Rafinesque distinguished his

plant from X. echinatum, stating that X. echinatum had "oval fruits,

with aggregated, echinate, and hooked thorns." Without doubt, he had

in mind not the true X. echinatum Murr. but rather the plant later

described by Moretti as X. italicum. The fruits of his X. maculatum he

described as "generally solitary half an inch long, nearly

cylindrical obtuse, with the two beaks scarcely perceptible and bent in,

covered with short, thick and rough thorns, rather soft, and not uncinate."

From these characters (especially the ones which we have emphasized

with italics) as well as from the habitat given ("near the sea-shore

and marshes"), we feel certain that by X. maculatum Rafinesque meant

the plant which was really the true X. echinatum Murr.

17. XANTHIUM ITALICUM Mor., Brugnatelli Giorn. fis., chim. Dec. II.,

5: 326. 1822; Reichenbach Iconographia Botanica 4: 22, tab.

323. 1826.

X. varians Greene, Pittonia 4: 59. 1899.

X. glanduliferum Greene, loc. tit., 61.

X. commune Britton, Manual 912. 1901.

£. Macounii Britton, he. tit. 913.*

Caulis ramosus, scaber, lineis atro-purpureis saepe maculatus, 3-10

(-18 fide Moretti) dm. altus. Folia cordata aut late ovata, lobata,

dentata, utrinque setulis adpressis scabra, petiolis adjectis 0.8-3 dm.

longa, petiolis laminis subaequantibus aut excedentibus. Fructuum

(PI. VII, f. 17; PL IX, ff. 25-30) corpus nunc cylindricum, nunc oblong-

um, nunc ovoideum, sed saepius late oblongum, facie exteriore glandu-

loso-pubescens et aculeis armatum, 1.3-1.8 cm. longum, 6-8 mm.

crassum; rostris plerumque incurvatis et ad apicem hamosis, hispidis,

5-7 mm. longis; aculeis saepius numerosis et tenuibus (rariter vel sub-

remotis vel subcrassis), infra hispidis usque ad medium, supra glabris,

ad apicem hamosis, 3-7 mm. longis.

DISTRIBUTION : Quebec, Connecticut and West Virginia to Saskatche-

wan, Washington, California and Oaxaca; southern Europe, Hawaiian

Islands, and probably elsewhere.

1 We are not able to determine satisfactorily the identity of X. Cavanillesii

Schouw (Ind. Sem. Hort. Haun.: 14. 1849; Ann. Sc. Nat. s6r. Ill, 12: 357. 1849).

Cavanilles' type plate (Cav. Icon. 3: tab. 221. 1794) cited by Schouw, shows the

fruits glabrous, except, of course, as to beaks and prickles. If this plate be assumed

to be accurate, then the plant figured was undoubtedly X. chinense Mill. If, as seems

just as likely however, Cavanilles' plate was rather generalized and lacking in

detail, as are many of his other plates, then his plant specimen probably possessed

hispid-aculeate fruit and belonged to X. italicum. Cavanilles' description of the fruit

(loc. cit., p. n) is devoid of details as to pubescence: "Fructus ovato-oblongus,

pollicaris, estque drupa sicca, undique aculeis uncinatis tecta, apice bifida, cuius

mix bilocularis." Schouw's own description of the fruit ("Involucre fructigero

ovali, inter aculeos et ad basin rostrorum hispidissimo; aculeis tenuiter subulatis,

strictis, infer ioribus retrorsum porrectis; rostris tenuibus, strictis, apice un-

cinatis"), based, however, upon a specimen from Buenos Ayres, by Didrichsen,

might well pass for that of X. italicum.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 41

SPECIMENS EXAMINED (partial list) : QUEBEC: Leamy's Lake, Sept.

n, 1891, /. Macoun (Hb. N. Y.). NEW HAMPSHIRE: Charlestown, dry

sandy open roadsides, Sept. 16, 1899, B. L. Robinson (Hb. Gray).

VERMONT: Springfield, open dry sandy roadside, Sept. 16, 1899, B. L.

Robinson (Hb. Gray). NEW YORK: Westport, shores of Lake Cham-

plain, Sept. 15, 1900, Dr. and Mrs. N. L. Britton (Hb. N. Y.; type of

X. commune Britton) ; Sandy Hill, along Champlain Canal, Stewart H.

Burnham 27 (Hb. Gray); Ogdensburg, Orra Parker Phelps 1212,1213

and 1214 (Hb. Gray); Hogansburg, banks of St. Regis River, eadem

1216 (Hb. Gray). CONNECTICUT: Plainfield, waste ground, Sept. 6,

1908, Bissell and Weatherby (Hb. Gray); Bridgeport, dry roadsides,

E. H. Eames I (Hb. Gray). PENNSYLVANIA: Lancaster, Oct. 7, 1901,

A, A. Heller (Hb. Field 430065; Hb. Gray; — a form with burs sug-

gesting X. pennsylvanicum). Lancaster, Dillerville Swamp, Sept. 24,

1889, John K. Small (Hb. Field 168555). MARYLAND: shore of Chesa-

peake Bay, south of Havre de Grace, George H. Shull 391 (Hb. Gray;

Hb. Mo. 85504). DISTRICT OF COLUMBIA: shore of Potomac River,

Sept. 3, 1876, Lester F. Ward (Hb. U. S. 130953). VIRGINIA: along

Potomac River, opposite Washington, D. C., Oct. 2, 1904, E. S. Steele

(Hb. U. S. 504661). WEST VIRGINIA: Hendricks, dry places along Black-

water River, /. M. Greenman 537 (Hb. Field 345708; Hb. Gray; form

matching type of X. commune Britt. very closely). INDIANA: Bluffton,

Sept. 9, 1897, Charles C. Deam (Hb. Field 123387); vicin. Bluffton, idem

548, (Hb. Mo. 85437). Kentucky: locality not stated, Dr. C. W. Short,

in 1842 (Hb. Gray). ILLINOIS: East St. Louis, Stockyards, Sept. 10,

1886, H. Eggert (Hb. Mo. 759571); sandy shore of Lake Michigan,

Frank C. Gates 50 (Hb. Field 458182); Champaign County, Urbana

Township, roadside, idem 2112 (Hb. Field 246297; an atypic form with

prickles more remote) ; Winthrop Harbor, idem 3228 (Hb. Field 345082

and 459041); Urbana, Sept. 19, 1901, A. Gilkerson (Hb. Gray; atypic

form with subremote prickles, approaching X. pennsylvanicum Wallr.) ;

Metropolis, banks of Ohio River, Aug. 14, 1902, H. A. Gleason (Hb.

Gray); Champaign, field, A. S. Pease 13009 (Hb. Gray); Chicago, along

sidewalk, Earl E. Sherjj 3079 (Hb. Field 480735 and 480736); Chicago,

along sidewalk, idem 3081 (Hb. Field 480739). IOWA: Ames, M.

Clapper 10 (Hb. Gray; Hb. Mo. 85441). MISSOURI: Courtney, in bot-

toms, B. F. Bush 1813 (Hb. Mo. 85601); Courtney, in bottoms, idem

ipio (Hb. Mo. 85458); Sheffield, idem 2216 (Hb. Mo. 85459); Webb

City, in cultivated fields, E. J. Palmer 1039 (Hb. Mo. 756627); Webb

City, waste places, idem 1303 (Hb. Mo. 85509 and 756631); Noel,

Butler Creek, gravel bars, idem 4219 (Hb. Mo. 716540). SOUTH DAKOTA:

Watertown, John J. Thornber, Aug., 1892, (Hb. Gray). NEBRASKA:

42 FIELD MUSEUM OP NATURAL HISTORY — BOTANY, VOL. IV.

Arcadia, Rev. J. M. Bates 5400 (Hb. Gray). TEXAS: Dallas, common on

prairie, B. F. Bush 1154 (Hb. Mo. 85477) ; San Antonio, Mr. and Mrs. J.

Clemens 953 (Hb. Mo. 808717); Graham, J. Reverchon 3279 (Hb. Mo.

85473). SASKATCHEWAN: "South Saskatchewan," J. Macounqi (Hb.

Gray; a small-fruited form). MONTANA: Great Falls, Sept. 16, 1885,

F. W. Anderson (Hb. Chi. 360828). COLORADO: Denver, common in

damp alkaline soil, Alice Eastwood 154 (Hb. Gray; Hb. Calif. 148085);

vicin. La Junta, Rose and Fitch 17507 (Hb. U. S. 760583). NEW

MEXICO: Nara Visa, Oct. 7, 1910, Geo. L. Fisher (Hb. Mo. 818395);

Mesilla Valley, Oct. 13, 1906, Paul C. Standley (Hb. Mo. 85488);

Mesilla Valley (Donna Ana County), College farm, Oct. 15, 1901, E. O.

Wooton (Hb. Mo. 85487); Mesilla Valley, Wooton and Standley 3129

(Hb. Field 223808). ARIZONA: Chiricahua Mountains, fields and sedi-

ments, J. C. Blunter 1487 (Hb. Field 242347; Hb. Gray; Hb. Mo. 85495;

Hb. N. Y.); Fort Apache, Rev. PaulS. Mayerhoff 88 (Hb. Field 113427).

WASHINGTON: Spokane, Frank 0. Kreager 537 (Hb. Gray); Spokane,

along creek, Sept. i, 1899, C. V. Piper (Hb. Gray); West Klickitat

County, sandy banks of Columbia River, W. N. Suksdorf 1583 (Hb.

Field 89751; Hb. Gray; Hb. Mo. 85499). CALIFORNIA: Los Angeles,

Dr. Hasse 4695 (Hb. N. Y.). SAN Luis POTOSI: San Luis Potosi, in

sandy places about the city, Dr. J. G. Schajfner 388 (Hb. Gray). Sina-

loa: near Mazatlan, Rose, Standley and Russell 14133 (Hb. N. Y.;

Hb. U. S. 636993). GUANAJUATO: Guanajuato, in 1891, Prof. A.

Duges (Hb. Gray). MORELOS: near Cuernavaca, C. G. Pringle 7330

(Hb. Gray). OAXACA: Valle de Etla, Rev. Lucius C. Smith 783 (Hb.

Gray). CUBA: Guines, H. A. Van Hermann 166 (Hb. Field 170583).

Moretti's original description of X. italicum is very full. According

to his own account, for a long time he had considered his species to be

X. echinatum Murr. and had sent specimens so labeled to various emi-

nent botanists such as De Candolle, Bertoloni etc. Finally he was forced

to the conclusion that the species was distinct from X. echinatum Murr.

and so he described it as new. He stated numerous characters in a

minutely detailed way. We quote his description of the fruit: "Nux

ovato-oblonga, undique aculeata, aculeis rigidis, apice simpliciter un-

cinatis, singulis undique echinatis. Rostra bina, patula, uncinata,

quorum uncini convergentes. Styli basi laeviter complanati, hinc

bifidi, e latere interiori uniuscuiusque rostri versus extremitatem

prodeuntes."

Moretti's plants were collected in several localities along the Po

River from Turin to Pavia. In the Bernhardi Herbarium (Hb. Mo.

85516) there exists a somewhat fragmentary and immature specimen

with the inscription "Xanthium echinatum frequens Tau-

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 43

rini." This is clearly one of Moretti's original specimens. In the

De Candolle Herbarium at Geneva there exists a fine mature specimen

collected by Moretti in the vicinity of Pavia, in 1819. This likewise

had been labeled Xanthium echinatum by Moretti.1 It matches well

the Turin specimen from the Bernhardi Herbarium and both of these

specimens agree perfectly with the plate published (from a specimen

sent by Moretti) by Reichenbach (loc. tit.) in 1826.*

X. varians Greene, while somewhat atypic in that its fruiting prickles

are slightly stouter, is easily seen to be a form of this species. X.

Macounii Britton is best considered as likewise a form of X. italicum.

Unfortunately, the single type specimen on which the description of

X. Macounii was based has immature fruits. These point, however,

to a somewhat atypic, rather sparsely aculeate form of X. italicum,

such as may be found growing occasionally among plants of the typical

form. Of X. glandulijerum Greene we have seen two specimens of the

type collection (Hb. Can.; Hb. Greene 19844). These would seem at

first to be closer to X. echinatum Murr. But the size and shape of the

achene and the character of the foliage all indicate a closer affinity with

X. italicum. At best, X. glandulijerum is probably to be considered as

only another of the mutant forms produced occasionally by X. italicum.

With X. italicum must be placed also X. commune Britton, originally

described from Westport, New York. The type specimen of X. com-

mune has the burs somewhat immature. These match closely those of

the type material of X. glandulijerum Greene. We have seen several

cases (e. g., Greenman 537, Hb. Gray) in which exactly the same form of

burs appeared along with other burs that were topical of X. italicum.

But whether this divergence from the typical form was due to hybridiza-

tion or to mere variation we are unable to state.8

18. XANTHIUM ACEROSUM Greene, Pittonia 4: 63. 1899.

Caulis flexuosus, lineis purpureis longitudinalibus saepe maculatus.

supra scaber, infra fere glabrescens, verisimiliter circum 4-9 dm. altus,

Folia late subcordato-ovata, obtusa, crenato-dentata, utrinque setulis

minutis adpressis scabra, petiolis adjectis 0.7-2 dm. longa, petiolis

laminis subaequantibus. Fructuum (PI. VII, f. *8; PI. IX, ff. 22-24)

corpus cylindricum, moderate glanduloso-pubescens, aculeis subremotis

armatum, 1.5-1.9 cm. longum et 6-7 mm. crassum; rostris tenuibus,

attenuatis, molliter pubescentibus, subrectis aut irregulariter incurvatis,

ad apicem minime hamosis, 7-8 mm. longis; aculeis vix numerosis,

1 We rely upon a large and excellent photograph of the sheet, furnished us through

the great kindness of the late M. Casimir De Candolle.

JWe have seen various European specimens collected, since Moretti's time, in

Italy, Corsica, Sardinia etc. Some of these were already labeled X. italicum.

1 For distinctions between X. italicum and X. pennsylvanicum, see p. 34.

44 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

gracilibus, remisse fere usque ad apicem pilis mollibus longiusculis

vestitis, rectis aut subrectis, ad apicem nunc dimidia parte eorum

hamosa, nunc vix uno aculeo hamoso, plerumque 6-9 mm. longis.

DISTRIBUTION: New York (where apparently adventive) ; Wisconsin,

North Dakota and Nebraska.

SPECIMENS EXAMINED: NEW YORK: Whitehall, Dresden Trestle,

Stewart H. Burnham 28 (Hb. Gray). WISCONSIN: Brown County,

Preble, Baird's Creek, Sept. 26, 1899, /. H. Schuette (Hb. Gray; Hb. U. S.

751759; the latter a rather immature and indistinctive specimen).

NORTH DAKOTA: near Fargo, Sept. 4, 1893, Edward L. Greene (Hb.

Greene 19835; — type) ; Minot, along Souris River, Dr. J. Lunell 80 (Hb.

Gray); Burleigh County, Bismarck, Aug. 23, 1913, idem (Hb. Greene

23707). NEBRASKA: Red Cloud, Rev. J. M. Bates 4747 (Hb. Gray).

It is with some hesitation that this species is here retained. The

fruiting burs, when slightly immature, resemble those of X. italicum.

When fully ripe, they appear to be intermediate between those on cer-

tain forms of X. pennsylvanicum Wallr. and those on certain forms of

X. speciosum Kearney. The brown, ripe burs have a body more or

less narrowly cylindrical; the prickles are mostly long and very delicate;

their hairs are soft and fine. However, as the specimens examined agree

very well among themselves, interference with the status of the species

seems scarcely wise or desirable at the present time.

19. XANTHIUM OVIFORME Wallr., Beitr. Bot. i11: 240. 1844.

X. silphiifolium Greene, Pittonia 4: 60. 1899.

Caulis simplex, infra levis, supra scabridus, 3-7 dm. altus. Folia

membranacea, indivisa, deltoideo-ovata, interdum vix trinervia,

inaequaliter sinuato-dentata, utrinque concoloria et setulis minutis

adpressis albidis aspera, ad basim vel orbiculata vel truncata vel

cordata, petiolis adjectis 0.7-2 dm. longa, petiolis laminis subaequan-

tibus. Fructus (PI. VII, f. 19; PI. X, ff. 1-3) non multi, demum maximi,

plerumque singulatim dispositi; fructuum corpore oblongo-ovato,

glanduloso-hispido aut rariter glabriusculo, aculeis armato, demum

circum 2 cm. longo et 1.2 cm. crasso; rostris validis, crassis, hispidis,

supra incurvatis, ad apicem valde uncinatis, circum 8 mm. longis;

aculeis remotis aut subremotis (aut fere confertis), validis, arcuatis et

corniformibus, fere usque ad apicem ferrugineo-hispidis (saltern ad

tergum et latera), ad apicem valde hamosis, ad faciem ventralem infe-

rioribus plerumque canaliculatis, (5-) 7-10 mm. longis.

DISTRIBUTION: Washington and probably Oregon; also adventive,

formerly at least, in southwestern Illinois.

SPECIMENS EXAMINED: WASHINGTON: Wawawai, C. V. Piper 3575

(Hb. Gray); Kittitas County, Rock Island, along water-courses,

Sandberg and Leiberg 446 (Hb. Gray); West Klickitat County, Sept. 28,

1883, sandy banks of the Columbia River, W. N. Suksdorf (Hb. Field

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 45

97447 and 211249; cotypes of X. silphiifolium Greene) ; without locality,

in 1879, idem (Hb. Gray); West Klickitat County, bottom lands of the

Columbia River, idem 189 (Hb. Gray). ILLINOIS: East St. Louis,

banks of the Mississippi River, Sept., 1847, Dr. George Engelmann (Hb.

Mo. 85552; form close to X. speciosum Kearney); cultivated by Asa

Gray, in botanical garden, Cambridge, Massachusetts, Oct., 1848, from

171 and ifia of Dr. George Engelmann, collected presumably in

September, 1847, at East St. Louis, 111., with the preceding specimen

(2 sheets in Hb. Gray; more typical than Engelmann's own specimen).

Greene (loc. tit.), in proposing nine species of Xanthium as new,

among them X. silphiifolium, laid no claims to a very profound knowl-

edge of the genus as a whole. Thus, with reference to Wallroth's mono-

graphic treatment of Xanthium, he says: "At present I know nothing

as to what his X. laevigatum, pungens, pennsylvanicum, xanthocarpum

or oviforme are. Presumably, however, they all belong to the Atlantic

slope of the continent. Little or nothing was known of this genus as

represented west of the Mississippi in the year 1842 [sic]. As all the

following are from far-western regions, I shall, in naming them as new,

incur small risk of becoming a manufacturer of synonyms."

Regarding three of these species, viz. X. pungens, X. pennsylvanicum

and"X. xanthocarpum," there need be no doubt as to the forms referred

to by Wallroth (cf. pp. 22, 31 and 15). Regarding X. laevigatum, we our-

selves are unable as yet to reach positive conclusions. The case of X.

oviforme, however, lends itself to very definite treatment. Wallroth's

description of this species is decisive and clear. In speaking of the

fruits he says (loc. tit.) : "fructibus sessilibus solitariis utrinque aequali-

ter rotundatis oviformibus (maximis), aculeis confertis validis corni-

formibus basi pilis articulatis ferrugineis densis vestitis cum rostris

intus contractis teretibus figura, vestitu et longitudine subconformibus

deliquescendo veluti obliteratis." We have also his footnotes regarding

the fruits. The first one says: "5) eifo"rmige, in Vergleich zur Pflanze

(d.h. dem vorliegenden Probestucke) sehr grosse, mit den Stacheln

dem Umfang einer kleinen Wallnuss oder Musskatennuss gleichende

Frucht."1

1 Two other footnotes in connection with the fruits are given by Wallroth. We

reproduce them verbatim herewith: "6) besonders stark ausgebildete, dicht-

stehende, 2'" lange Stacheln, welche bis uber die Halfte mit dicht-und abstehenden,

gegliederten Haaren umstarrt sind, am oberen Theile aufwarts, in der Mitte etwas

abwarts und am Grunde ruckwarts gerichtet sind und den ganzen Fruchtkorper

allenthalben dich und gleichmassig umstarren;

" 7) mit den Stacheln fast gleichformige, nur doppelt so starcke, nach oben rinnen-

fdrmig ausgehohlte Stacheln, welche wegen gegenseitiger Aehnlichkeit mit den Sta-

cheln gleichsam zu verschwinden oder im Vergleich mit anderen Arten zu fehlen

scheinen." — The grooved ventral surfaces exhibited by certain of the large basal

prickles on the fruits of this species seem indeed an unique character.

46 FIELD MUSEUM OF NATURAL HISTORY — BOTANY, VOL. IV.

A comparison of Wallroth's Latin description with the others in his

monograph shows two outstanding features for his X. oviforme. The

fruits were very large and were covered with strong, horn-shaped prickles,

these densely clothed at their base with jointed, reddish hairs. Further-

more, Wallroth based his species directly upon Hooker's Xanihium

canadense from North America ("X. Canadense Hook, in lit. (herb,

general berol.), nee Herm., Mill, et Linn. Angeblich in Nordamerika

und vermuthlich in Canada.").

Thus, Wallroth had seen a plant in Berlin labeled "X. canadense"

by Hooker, but which appeared distinct from all other specimens

because of its mammoth burs and their horn-shaped prickles. On

reference to Hooker's Flora Boreali-Americana, a work published in

1840 and which Wallroth appears not to have seen, we find the basis of

Wallroth's species. Hooker (loc. cit. 308), instead of giving an extended

range or list of stations as in the case of many other species, gave

merely, "Hab. Canada? North-West coast of America. Douglas."

So the plant determined by Hooker as X. canadense was a plant collected

by Douglas along the northwest coast of (North) America.1 But it was

in this same region that the type of X. silphiifolium Greene was ob-

tained. Greene's type was collected by Suksdorf, on the banks of the

Columbia River,2 September, 1883. While this type itself (in Hb. U. S.)

is at present inaccessible to us, we have seen the two excellent cotypes

in the Herbarium of Field Museum and also the two other specimens

by Suksdorf in Gray Herbarium. These all agree well with each other

in having large, coarse burs, with very strong, elongate, reddish-hispid,

horn-shaped (arcuate), hooked prickles and somewhat similar beaks;

the lower prickles on each bur tend to be strongly grooved upon the

ventral face. The specimen collected by Suksdorf on bottom lands of

the Columbia River (no. 189) is particularly instructive. It is accom-

panied by one mature bur, much larger than the rest, a bur such as

most collectors might shrink from trying to press. This bur is really of

gigantic proportions, having a size observed by us so far in only two

other species (X. campestre and X. speciosum). The body proper is

2.3 cm. long and about i cm. thick. The prickles and beaks measure

from 8 mm. to 10 mm. in length, giving the bur a total expanse of 3.9

cm. in length and about 2.8 mm. in width.

Without question, it was this large-fruited form of Xanthium that

1 Had Hooker seen plants of this species from other collections it is clear that he

would have cited them, since his citations of range appear in each case to be as

complete as his data at that time would permit.

2 An examination of Hooker's text shows that a large proportion of the other

Douglas plants studied by Hooker had likewise come definitely from the banks of

the Columbia River.

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 47

was the basis of Wallroth's X. oviforme and the identity of the species

is thus seen to be settled too clearly to permit of its name being

displaced by the more recent name X. silphiifolium}'

20. XANTHIUM SPECIOSUM Kearney, Bull. Tor. Bot. Club 24: 574,

1897.

X. bubalocarpon Bush, Kept. Missouri Bot. Gard. 17: 123,

Caulis erectus, robustus, ramosus, ad basim demum 2.5 cm. crassus,

plus minusve (infra obtuse et supra acute) quadrangulatus, supra lineis

purpureis maculatus, papilloso-scabridus praesertim supra, 1-1.5 m-

altus. Folia late triangulato-ovata, obtuse et non profunde 3~5-lobata,

dentata, crassiuscula, ad basim cordata, utrinque setulis aut papillis

minutis adpressis scabra, petiolis adjectis 1-3.5 <"&« longa et 0.8-2.2 dm.

lata, petiolis laminis subaequantibus. Fructus (PI. VII, f. 20; PI. X,

ff . 4-6) maximi, ovoidei aut conici; corpore ovato-cylindrico, vix aspecta-

bili, glanduloso-pubescenti, aculeis armato, demum circum 2-2.3 mm-

longo et 7-8 mm. crasso; rostris attenuatis, hispidis, subrectis aut

incurvatis, ad apicem hamosis, 6-n mm. longis; aculeis confertis, sub-

tenuibus, besse inferiore aut dimidio inferiore hispido, versus apicem

levibus, ad apicem hamosis, plerumque 7-9 mm. longis; toto fructu

(aculeis et rostris adjectis) demum 3-4 cm. longis et 2-2.5 (~3 ex descrip-

tionibus Kearneyi et Bushii) cm. latis.

DISTRIBUTION: Tennessee to South Dakota, Texas and Mexico;

adventive in Maine and Vermont.3

SPECIMENS EXAMINED:* MAINE: North Berwick, wool-waste heap,

Sept., 1895, John C. Parlin (Hb. Gray). TENNESSEE: Cocke County,

between Paint Rock and Del Rio, along French Broad River, Thos. H.

Kearney, Jr., 785 (Hb. Greene 19829; Hb. Mo. 85550; Hb. N. Y.;

cotypes). MISSOURI: Cass County, roadside, prairie, Aug., 1869, G. C.

1 Since the above was written, we have been very fortunate in receiving from

the Herbaria of the British Museum of Natural History and the Royal Botanical

Gardens at Kew, excellent photographs of the Douglas plants. Our conclusions, as

presented above, are seen to be confirmed most emphatically. Both specimens match

precisely the Suksdorf material of X. silphiifolium. The inscription on the British

Museum sheet, as copied for us, reads, "X. strumarium Willd. Sandy island and

banks of the Columbia Douglas 1825 Xanthium canadense Spreng. Hook Fl. Bor.-

Am. i. p. 308." That upcn the sheet at Kew (a sheet originally in Bentham's private

herbarium) reads, "Xanthium canadense Spr. Hook Fl. Bor. Am. I. 308. Am. bor.

occ. Douglas 1829 [sic] X. oviforme Wallr. cotype."

2 Piper (Contrib. U. S. Nat. Herb. 1 1 : 550. 1906) has referred X. silphiifolium

Greene to this species. But, as will be apparent from the foregoing paragraphs

(C/. X. oviforme, p. 44) if X. silphiifolium, which is synonomous with X. oviforme,

shall subsequently be proved conspecific with X. speciosum, then, by the same proof,

X. speciosum will have been shown to be synonomous with X. oviforme.

* Cf. footnote i, p. 27.

4 We have seen two specimens by H. Eggert, one at least from Illinois (pre-

sumably at East St. Louis), collected Sept. 13, 1874 (Hb. Gray; Hb. Mo. 85381).

These appear to be X. speciosum, but the prickles are subremote and rather stout and

suggest X. oviforme Wallr. very strongly.

48 FIELD MUSEUM or NATURAL HISTORY — BOTANY, VOL. IV.

Broadhead (Hb. Mo. 85553). ARKANSAS: Fulton, B. F. Bush 2408

(Hb. Mo. 85375). SOUTH DAKOTA: Deadwood, waste ground, alt. 1430

m., John Murdoch, Jr., 4334 (Hb. Gray). KANSAS: Kiowa County, low

ground, A. S. Hitchcock 726 (Hb. Gray; Hb. Mo. 85525). OKLAHOMA:

Hugo, moist limestone soil, E. J. Palmer 9015 (Hb. Mo. 794481).

TEXAS: Dallas, prairie, B. F. Bush 1185 (Hb. Gray; Hb. Mo. 85380;

type specimens of X. bubalocarpon Bush); Pease River, near Vernon,

salt bottoms, Sept. 18, 1903, H. Eggert (Hb. Mo. 85558 and 85559);

Dallas, Oct. 10, year not stated, /. Reverchon (Hb. Mo. 85557); Coombs

Branch, Aug. 24, 1901, idem (Hb. Mo. 85556 and 85562); Coombs

Branch, Oct. 9, year not stated, idem, (Hb. Mo. 85479) ; Dallas, prairie,

Aug. 30, 1901, idem (Hb. Gray; Hb. Mo. 85378); Dallas, prairie, idem

2580 A (Hb. Mo. 85379); Luck's Mill, Aug. 25, year not stated, idem

(Hb. Mo. 85560 and 85561); Oak Cliff, wastes, Aug. 30, 1901, idem

(Hb. Mo. 85376 and 85377). l

While appearing in rare cases to intergrade or perhaps hybridize

with X. oviforme Wallr., X. speciosum seems, nevertheless, on the whole

to be worthy of retention as a distinct species. It is apparently best

distinguished from that species by the closer, more slender and less

arcuate prickles, which do not suggest horns, and by a tendency of the

entire involucre, when mature, toward a yellowish or yellowish-brown

color rather than toward the dark-reddish color shown in X. oviforme.

The several sheets of type material (Kearney 785) that we have

examined are of a slightly immature stage and the burs are not fully

ripened. But Kearney (loc. tit.} described the burs as "2.5-4 cm. long,

2.5-3 cm' wide (including the prickles) " and, as some of the slightly

immature burs are observed by us on the type material to have become

3.5 cm. long and 2.5 cm. wide (including the prickles), it is certain that

Kearney's measurements correctly represent the mature fruits.

In describing his X. bubalocarpon, Bush (loc. tit.} stated: "This

very distinct species is more nearly related to X. speciosum Kearney,

but is easily distinguished from that species by the much larger burs

which are of an entirely different shape." However, on reading his

description, we find given the measurements " 2.5-4 cm. long, including

the prickles." It is seen that these measurements are practically

identical with those given by Kearney for X. speciosum. And, indeed,

when we compare the excellent type material of X. bubalocarpon (Bush

1185) with that of X. speciosum, we can detect no specific difference.

1 We have seen no typical material of X. speciosum from Mexico. Certain some-

what anomalous forms from there appear, however, to be best regarded as belonging

to this species (e.g., J. N. Rose 2433, near San Juan Capistrano, Zacatecas, Hb. U. S.

301344; Rose, Painter and Rose 0032, near Tehuacan, Puebla, Kb* U. S. 453446).

APRIL, 1919. XANTHIUM — MILLSPAUGH AND SHERFF. 49

The two are well connected, furthermore, by the various other specimens

of differing stages of maturity examined by us and cited above.

21. XANTHIUM CAMPESTRE Greene, Pittonia 4: 61. 1899.

Caulis saepe lineis purpureis brevibus maculatus, supra scabridus,

5-8 dm. altus. Folia subcrassa, subdeltoidea, dentata aut serrata, non

perspicue lobata, ad basim truncata aut cordata, supra scabra, infra

scabro-pubescentia, petiolis adjectis 6-17 cm. longa, petiolis laminis

subaequantibus. Fructus (PI. VII, f. 21; PI. X, ff. 7-8) maximi, maxi-

mam partem singulatim dispositi, ovoideo-conici; corpore non saepe

aspectabili sed aculeis plerumque numerosis et densissimis armato,

demum circ. 2.3-2.6 cm. longo et 1-1.3 cm. crasso; rostris late diver-

gentibus, infra crassis et pubescentibus, supra glabratis et tenuiter

hamosis, 6-7 mm. longis; aculeis teretibus, arcuatis, infra (demum

ferrugineo-) hispidissimis, supra glabris et ad apicem hamosis, circum

5 mm. longis; toto fructu (aculeis et rostris adjectis) demum 2.8-3.5 cm-

longo et 2-2.5 cm- lato.

DISTRIBUTION: California.

SPECIMENS EXAMINED: CALIFORNIA: Chico, June 27, 1890, Edward

L. Greene (Hb. Greene 19837; type); Chico-Hamilton Road, 9.5 km.

northwest of Chico, A. A. Heller 11629 (Hb. Calif. 179073; Hb. Field

426983; Hb. Gray; Hb. Greene 51204; Hb. Mo. 748145; Hb. N. Y., a

more mature specimen, with the burs just turning reddish in color.)

This species is distinguished from most others by the great size of its

burs, these coming to have, when well-developed, an expanse (including

the beaks and prickles) of about 3.5 cm. in length and 2.5 cm. in width.

In Greene's type specimen, the prickles are remote enough to permit a

view of the body of the bur. The several somewhat immature speci-

mens by Heller have the prickles more densely grouped together, leav-

ing the body mostly concealed. The burs have a decidedly yellowish-

green color until nearly mature, when they turn to a reddish color,

rather closely resembling those of X. oviforme Wallr.

INDEX

Acanthoplia Wallr. 14

Acanthoxanthiura DC. 14

A canthoxanthium

spinosum Fourr. 14

Anoplia Wallr. 15

Campy lorrhyncha Wallr. 15

Euxanthium DC. 15

Lappa canadensis

minor i Ray 26

Orthorrhyncha Wallr. 15

Xanthium L. 12

abyssinicum Wallr. 16

acerosum Greene 9, 43

acutilobum M. & S. 35

acutum Greene 31, 9, 33, 34, 35

affine Greene 31, 9, 33, 35

ambrosioides H. & A. 17

americanum Walt. 20, 10, 22, 23

antiquorum Wallr. 16, 17, 20

arcuatum M. & S. 25

australe M. & S. 37

brasilicum Velloz. 37

brevirostre Wallr. 16, 17

bubalocarpon Bush 47, 48

californicum Greene 31, 9, 33, 34, 35,

36

calvum M. & S. 35

campestre Greene 49, 39

canadense Mill. 20, 17, 46

carolinense Dill. 17

Cavanillesii Schouw. 40

cenchroides M. & S. 30

chinense Mill. 17, 10, 23, 25, 26, 27,

32, 37, 39, 40

commune Britt. 40, 29, 41, 43

Woptoni Cockll. 28

crassifolium M. & S. 35

crassum Raf. 16

cuneatum Moen. 26

curyescens M. & S. 25

cylindricum M. & S. 23, 9

discolor Wallr. 16, 17, 21

echinatum Murr. 38, 10, 22, 23, 33,

42,43

Xanthium

elatius a majus americanum Moris. 26

eriocarpon Wallr. 17

glabratum Britt. 17

glanduliferum Greene 40, 9, 43

globosum Shull 23, 9, 10

homothalamum Spr. 37

inaequilaterum DC. 17

inflexum Mack. & Bush 30

italicum Mor. 40, 10, 27, 33, 34, 38, 43

laevigatum Muhl. 45

leptocarpum M. & S. 28, 26, 27

leucocarpon Wallr. 17

longirostre Wallr. 17, 22, 37

Macounii Britt. 40, 43

macrocarpum DC. 26, 10, 27

glabratum DC. 17

maculatum Raf. 38, 16, 39

majus canadense Herm. 26

occidentale Bertol. 17. 22. 23

oligacanthum Piper 28

orientale L. 26, 10, 16, 20, 25, 27, 39

oviforme Wallr. 44, 47, 48, 49

palustre Greene 36

pennsylvanicum Wallr. 31, 10, 22,

25, 36, 39, 4i, 44, 45

eglandulosum Wallr. 31, 34, 32

glandulosum Wallr. 31, 34

pensylvanicum Wallr. 31

priscorum Wallr. 17, 1 6

pungens Wallr. 17, 22, 23, 45

riparium Lasch. 39

Roxburghii Wallr. 16, 17

saccharatum Wallr. 31, 34

silphiifolium Greene 44, 45, 46, 47

speciosum Kearn. 47, 27, 44

spinosum L. 14, 10

strumarium L. 16, 10, 17, 22

antiquorum Ball. 16

brasilicum Bak. 37

undulatum Raf. 16

varians Greene 40, 43

Wootoni Cockll. 28

xanthocarpon Wallr. 14, 15, 45

PLATE VII.

P. I. X. spinosum L. Eggert (Hb. Mo. 720835).

F. 2. X. strumarium L. Brandegee (Hb. Calif. 131246).

F. 3. X. chinense Mill. Greenman 47 (Hb. Field 189512; topotype; atypic in hav-

ing prickles slightly pubescent at base.)

F. 4. X. cyhndricum Millsp. and Sherff. Small and Huger (Hb. Field 401312; type).

F. 5. X. globosum Shull. Shull (Hb. Field 477328; lineal descendant of type mate-

rial).

F. 6. X. arcuatum Millsp. and Sherff. Lucy (Hb. Field 4953; type).

F. 7. X. curvescens Millsp. and Sherff. Eggleston 1420 (Hb. Gray; type).

F. 8. X. leptocarpum MiJJsp. and Sherff. Jones (Hb. Field 430860; type).

F. 9. X. Wootoni Cockll. ex De Vries. T. D. A. Cockerell, Las Vegas, New Mexico,

Oct. 4, 1901 (Hb. N. Y.; authentic material from author).

F. 10. X. cenchroides Millsp. and Sherff. Reverchon 2332 (Hb. Mo. 85563; type).

F. ii. X. inflexum Mack, and Bush. Bush 1916 (Hb. Mo. 85520; type material).

F. 12. X. pennsylvanicum Wallr. Lansing 3532 (Hb. Field 346590).

F. 13. X. calvum Millsp. and Sherff. Baker 1760 (Hb. Calif. 131236; type).

F. 14. X. palustre Greene. Walker 973 (Hb. Calif. 128022).

F. 15. X. australe Millsp. and Sherff. Palmer 275 (Hb. U. S. 463216; type).

F. 16. X. echinatum Murr. Miss M. E. Blatchford, Prouts Neck, Me., Sept., 1898

(Hb. Gray).

F. 17. X. italicum Mor. B. L. Robinson, Springfield, Vt., Sept. 16, 1899 (Hb. Gray).

F. 1 8. X. acerosum Greene. Lunell 80 (Hb. Gray).

F. 19. X. oviforme Wallr. Suksdorf 189 (Hb. Gray).

F. 20. X. speciosum Kearn. Bush 1185 (Hb. Mo. 85380; type material of X.

bubalocarpon Bush).

F. 21. X. campestre Greene. Heller 11629 (Hb. Gray; topotype).

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE VII.

FRUITS OF XANTHIUM (Natural size)

PLATE VIII.

X. spinosum L.

F. i. C. R. Orcutt, Port Harford, Calif., Nov. 23, 1886 (Hb. Mo. 85586).

F. 2. Heller 12655 (Hb. Mo. 802945).

F. 3. Griffiths 7344 (Hb. Mo. 85583).

X. strumarium L.

F. 4. Hb. Schlagintweit, drained lake basin of Kashmir, vicin. Srinagger, prov.

Kashmir, India, Oct. 2-20, 1856 (Hb. Gray).

F. 5. T. Thomson, Plan. Ganget. Sup., India Orient. (Hb. Gray).

F. 6. Fernald, Crescent Beach, Revere, Mass., Oct. 20, 1912 (Hb. Gray).

F. 7. W. Schirnper 1343, in agris Sorghi pr. Sabra Abyssinia (Hb. Gray; cotype

of X, abyssinicum Wallr.).

F. 8. Kotschyi iter nubicum 319, ad ripas Nili albi prope Chartum in provincia

Sennar (Hb. Gray; cotype of X. antiquorum Wallr.).

X. chinense Mill.

F. 9. Rose, Fitch and Russell 4351 (Hb. U. S. 760483, topotype of X. occi-

dentale Bertol.).

F. 10. Greenman 47 (Hb. Field 189512, topotype).

F. ii. Brown and Britton 374 (Hb. Field 203890).

F. 12. Bush 1348 (Hb. Mo. 85428).

F. 13. Phelps 989 (Hb. Gray).

Ff. 14 and 15. Anonymous (Hb. Fla. Agricult. Coll. no. 1279 in Hb. Field,

no. 234909).

X. cylindricum Millsp. and Sherff.

Ff. 16, 17 and 18. Small and Huger (Hb. Field 401312, type).

Ff. 19 and 20. (Hb. N. Y., cotype).

X. globosum Shull.

F. 21. Shull (Hb. Field 477328, lineal descendant of type material).

Ff. 22 and 23. Shull (Hb. Field 477326, topotype identical with type).

X. arcuatum Millsp. and Sherff.

Ff. 24, 25 and 26. Lucy (Hb. Field 4953, type).

X. curvescens Millsp. and Sherff.

Ff. 27, 28 and 29. Eggleston 1420 (Hb. Gray, type).

X. leptocarpum Millsp. and Sherff.

Ff. 30, 31 and 32. Jones (Hb. Field 430860, type).

X. Wootoni Cockll. ex De Vries.

F. 33. Deane, South Boston, Mass., Oct. 4, 1909 (Hb. Williams in Hb. Gray).

F. 34. Horner B 272 (Hb. Gray).

F. 35. Piper (Hb. N. Y., cotype of X. oligacanthum Piper).

F. 36. Cockerell (Hb. Gray, author's material).

X. cenchroides Millsp. and Sherff.

Ff. 37 and 38. Reverchon 2332 (Hb. Mo. 85564, cotype).

F. 39. Reverchon 2332 (Hb. Mo. 85563, type).

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV. PLATE VIII.

2 3

10

II 12 13

16 17 18

24.

25 26

3° 31

20

21

22 23

28

27

29

33

34 35

37 38

FRUITS OF XANTHIUM (Natural size)

US* ART

UNIVCESITY Of ILLINOIS

URBANA

PLATE IX.

X. inflexum Mack, and Bush.

F. i. Bush, 1916 (Hb. Gray, type material).

F. 2. Engelmann (Hb. Mo. 85551).

F. 3. Bush 1806 (Hb. Mo. 85522).

F. 4. Bush 1806 (Hb. Gray).

X. pennsylvanicum Wallr.

F. 5. Greene (Hb. Greene 19822; type of X. calif ornicum Greene).

F. 6. Sanford (Hb. Greene 19819, type of X. acutum Greene).

F. 7. Reverchon 2589 (Hb. Mo. 85546).

F. 8. Suksdorf 1584 (Hb. Mo. 85374; cotype of X. affine Greene).

F. 9. Lansing 3532 (Hb. Field 346590).

F. 10. Heller 7550 (Hb. N. Y.).

X. calvum Millsp. and Sherff.

Ff. ii and 12. Baker 1760 (Hb. Calif. 131236, type).

X. palustre Greene.

F. 13. Greene (Hb. Greene 19834, type material).

F. 14. Greene (Hb. Greene 10833, type material).

F. 15. Walker 973 (Hb. Calif. 128022).

X. australe Millsp. and Sherff.

F. 1 6. Palmer 275 (Hb. U. S. 463216, type).

F. 17. Dr. Mertens, Valparaiso, Chile (ex Hb. Acad. Petrop., in Hb. Gray).

F. 18. Morong 807 (Hb. N. Y.):

X. echinatum Murr.

F. 19. Sturteyant (Hb. Mo. 85500).

F. 20. Victorin 1056 (Hb. Gray).

F. 21. Miss M. E. Blatchford, Prouts Neck, Me., Sept., 1898 (Hb. Gray).

X. acerosum Greene.

F. 22. J. H. Schuette, Baird's Creek, Preble, Brown County, Wis., Sept. 26, 1899

(Hb. Gray).

F. 23. Burnham 28 (Hb. Gray).

F. 24. Lunell 80 (Hb. Gray).

X. italicum Mor.

F. 25. Suksdorf 1583 (Hb. Field 89751, cotype of X. varians Greene).

F. 26. Macoun 11415 (Hb. Can. 11415, type of X. Macounii Britton).

F. 27. Macoun 10910 (Hb. Can. 10910, type material of X. glanduliferum

Greene).

F. 28. Sherff 3081 (Hb. Field 480739, matching fruits on Moretti's specimen in

Hb. De Candolle).

F. 29. Bruyas, gravelly fields along banks of the Arc River, Aix Bouches-du-

Rhone, France, Sept. 27, 1884 (Hb. Field 331608).

F. 30. Rose and Fitch 17507 (Hb. U. S. 760583).

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE IX.

2$ 26

29 30

FRUITS OF XANTHIUM (Natural Size)

ilBSARY

UNIVERSE OF ILLINOIS

URBANA

THE LIBRARY OF THE

JUL241943

UNIVERSITY OF

PLATE X.

X. oviforme Walk1.

F. I. Suksdorf (Hb. Field 211249, cotype of X. silphiifolium Greene).

F. 2 and 3. Suksdorf 189 (Hb. Gray, topotype of X. silphiifolium Greene).

X. speciosum Kearn.

F. 4 and 6. Bush 1185 (Hb. Mo. 85380, type material of X. bubalocarpon

Bush).

F. 5. Kearney 785 (Hb. N. Y.; cotype).

X. campestre Greene.

F. 7. Greene (Hb. Greene 19837, type; an atypic bur on lower part of plant;

burs higher up on type are more as in f. 8).

F. 8. Heller 11629 (Hb. Gray, topotype).

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE X

FRUITS OF XANTHIUM (Natural size

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE XI.

XANTHIUM CURVESCENS

LIBRARY

UNIVERSITY OF ILLINOIS

URBAN A

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE XII.

REVISION OF XANTHIUM.

•J PHI. I WsrAK* '

PLANTS OK THE PACIFIC COAST

XANTHIUM CALVUM

LIBRARY

UNIVERSITY OF ILLINOIS

URBAN&

FIELD MUSEUM OF NATURAL HISTORY.

BOTANY VOL. IV, PLATE XIII.

XANTHIUM AUSTRALE

OF ILLINOIS

URBANE