A

Field Museum of Natural History.

Publication 187.

Botanical Series. • Vol. II, No. 11.

I. CONTRIBUTIONS TO NORTH AMERICAN

EUPHORBIACEAE— VI

II. VEGETATION OF ALACRAN REEF

BY

Charles Frederick Millspaugh

Curator Department of Botany.

Chicago, U. S. A.

April, 1916.

Field Museum of Natural History.

Publication 187.

Botanical Series. Vol. II, No. 11,

I. CONTRIBUTIONS TO NORTH AMERICAN

EUPHORBIACEAE— VI

II. VEGETATION OF ALACRAN REEF

BY

Charles Frederick Millspaugh

Curator Department of Botany.

Chicago, U. S. A.

April, 19 1 6.

Issued Apr. 28, 1916.

contributions to north american

euphorbiace;e-vi

CHARLES F. MILLSPAUGH, M. D.

Chamaesyce S, F. Gray, Nat. Arr. Brit. PL 2:260. 1821.

Leaves opposite, inaeqtiilateral; inflorescence solitary or capitulate,

axillary and terminal; bracteoles plumose or ciliate; seeds minute,

ovoid or elongate-ovoid, more or less quadrangular the facets smooth or

transverse-rugulose .

Type species: Euphorbia peplis Linn. Sp. PI. 652. 1753.

Chamaesyce barbicarina sp. nov.

Plants semi-erect, about 2dm. high, annual. Stems many, from a

but slightly raised rootstalk ; branches many, virgate, terete, long-pilose

especially upon the upper surface. Inflorescence solitary in the axils

of the terminal branchlet leaves. Leaves opposite, 5-8 x 2-4mm.,

ovate, obtuse, broadest at the roimded apex, base strongly auriculo-

oblique, glabrous the thickened margin crenate-dentate; petioles about

I mm., hairy; stipules broadly triangular-lanceolate, lacerate. In-

volucres turbinate, glabrous without and within; peduncle about the

length of the involucre (in fruit twice the length); involucral lobes

triangular, ciliate; siilcus shallow; glands scutelliform; appendages white,

irregular-ovate, margin crenate or 2-3-crenate-dentate; bracteoles none;

male pedicels few, short; female pedicel ciHate-hairy; styles short,

bilobed at the apex. Capsule obpyriform, glabrous except on the blunt

keels of the otherwise smooth carpels which are long-ciliate fringed;

seeds red, ovoid, acute, .9 x .6mm., angles sharp, facets marked by a few

very slightly raised irregtilar and broken transverse ridges.

Between Ch. dioica and Ch. yucatanensis but readily distinguished

from both by the peculiar ciliate-fringed keels of the carpels.

Sitilpech Road, November, 1895, Gaumer 939a (Type sheet,

Field Mus. cat. no. 196,352.) It was gathered as a part of a mass of Ch.

rutilis by the collector. Also collected at Chichankanab, Gaumer 1432,

2074; and at Pocoboch 2405.

401

402 Field Museum of Natural History — Botany, Vol. II

Chamaesyce cozumelensis comb. nov.

Etiphorbia cozumelensis Millsp. Field. Mus. Bot. 2:261. 1900.

A large number of sheets of this species show an intergradation from

the absolutely glabrous and glaucous original collection, on Cozumel

Island, through a form with a few long, scattered hairs in the capsular

sulci {E. cozumelensis pilosulca Millsp. ibid. 262) ; a form with a few long

hairs on the nodes, petioles and leaves; to plants densely long-pilose

throughout. The extremes of these plants appear like widely different

species but the characters do not warrant the application of even varietal

names.

The distribution of the forms is as follows: The glaucous form —

Cozimiel Island, Millspaugh 1604, 1606, 1608, i6og, 1611; the form with

the capsular siilci hairy — Cozumel Island, Millspaugh 1501, 1502;

the form with the nodes, petioles and leaves long-pilose — Cozimiel

Island, Millspaugh 4Q, 53, Chichankanab, Gaumer 1456; whole plant

densely long-pilose — Mugeres Island, Millspaugh 24, Izamal, Silam

and Progreso, Gaumer J14, 62Q, 1887, 2407.

Chamaesyce hirta (L.) Millsp. Field Mus. Bot. 2:303.

I have gathered a large number of forms of this species from many

localities in Hawaii, south China, Straits Settlements, Java, the PhiHp-

pines, Burma, India, and from Bermuda, Florida and the Bahamas

through the West Indian islands, Mexico and South America to Pemam-

buco, Brazil. With all this material and a large number of sheets from

other collectors I can not satisfy myself that there is any specific dif-

ferentiation between E. hirta and E. pilulifera L,, capitata Lam., globuli-

fera Kth., verticillata Veil., nodiflora Steud., procumbens DC, obliterata

Jacq., ophthalmica Pers., discolor Engelm., gemella Lag., and Karwin-

skyi Boiss. the type material of all of which I have examined. These

are only intergradient forms and there are a multitude of others that

have luckily escaped specific nomination.

Chamaesyce Rosei sp. nov.

Annual, short-crispid-multicellular hairy. Root straight and deep;

stems many, terete, wiry; intemodes long; branches profuse, ascending.

Inflorescence in terminal, globose heads. Leaves inaequilateral,

narrowly lanceolate, 13-25 x 3-6mm., crisp-hairy on both surfaces and

with a broad, deep-red, central line of maciilation; apex acute; base

narrowing to the petiole; margin shallow-toothed toward the apex;

petioles short (about 2mm.); stipules mere aristate teeth about .8mm.

long. Involucres turbinate, roseate, sessile or nearly so, thin walled,

the outer surface pubescent the inner densely bearded; lobes deltoid.

April, 1916. Euphorbiace^e — Millspaugh 403

aristate; sulcus V-shaped, the fundus occupied by 2-3-aristate lobes;

glands minute, stipitate, cupulate; appendages roseate, distant from the

glands and but Httle larger, inserted about half way down the stipe; male

flowers about 6, short, absent in many involucres of each cluster;

filaments glabrous; female flower short pedicelled; ovary densely pubes-

cent ; styles roseate, bifurcate two-thirds their length, the branches di-

varicate and somewhat capitulate at the stigmatic tips. Capsule

strongly tricoccous, bearing very short, thick, crispid, golden, multicel-

lular hairs; seeds pink-ashen, ovate-quandrangular, acute, .8 x .5mm.,

angles sharp, facets marked by irregular, complete and incomplete

transverse ridges.

Near Ch. hirta (L.) Millsp.

Mexico, along an arroyo in the vicinity of Alamos, State of Sonora,

Rose, Standley 6° Russell, March 13, 1910, 12728 (Type in herb. New

York Botanical Garden).

Chamaesyce vallis-mortae sp. nov.

Perennial from a long, cylindrical root; densely woolly-pubescent

above. Stems many, \dry, divergently branching toward the tips.

Inflorescence solitary in the leaf axils of the branchlets. Leaves thick,

ovate, cordate, roimded at the apex, entire, 5 x 4 — 6 x 5mm., densely

woolly on both surfaces; petioles about imm. long; stipules short,

triangular, cihate. Involucres campanulate; peduncle about one-third

the length of the tube; outer surface woolly, inner surface fasciculate-

hairy; lobes triangular; sulcus deeply V-shaped, the fundus unoccupied;

glands green, longitudinal, scutelliform; appendages large, white,

flabelliform, the outer margin papulo-ciliate and often slighty 3-crenate;

male flowers about 6, glabrous; female flower pedicellate; ovary woolly-

pubescent; styles bifid two-thirds their length, the branches divergent

not swollen at the stigmatic tips. Capsule obpyriform, hairy; seeds

salmon-color, quadrangular-ovate, pointed, the angles rounded, facets

smooth or nearly so.

Near Ch. tonsita Millsp.

California, Death Valley between Mohave and Keeler, alt. 750

meters, June 21, 1891, Coville b' Funston 1008 (Type in U. S. National

Herbarium cat. no. 16203).

Chamaesyce tamaulipasana sp. nov.

Annual, prostrate, pilose. Stems many from the thickened rootstalk ;

branches unilateral on the stems, densely foHate; branchlets very short.

Inflorescence solitary in the axils of the branchlet leaves. Leaves ap-

pressed, inaequilateral, ovate, acute, cordate, entire, 3.5x2- 5x3

404 Field Museum of Natural History — Botany, Vol. II

mm., long-crisp-hairy on both surfaces; petioles short, thick; stipules

elongate-linear, hairy. Involucres elongate-turbinate narrowing to

the peduncle which is about the length of the tube; both surfaces pilose;

sulcus U-shaped with a short, linear lobe in the fundus; glands trans-

verse, ovoid, short stipitate, scutelliform; appendages fiabelliform,

twice the width of the glands, entire, the margin papilliform-ciliate;

male flowers few; pedicels glabrous; filaments very short; female flower

pedicellate; ovary densely pilose; styles bifurcate to the middle, the

stigmatic lobes divergent. Capsule obpyriform, pilose, strongly tri-

coccous; seeds red-ashen, elongated ovoid-quadrangular, pointed, 1.2 x

.5mm., angles sharp; facets nearly smooth, indistinctly marked by a

median longitudinal line approached on both sides by numerous, ir-

regular, faint, transverse ridges.

Near Ch. velleriflora (Boiss).

Known only from the vicinity of Victoria, Tamaulipas, Mexico,

where it was collected by Dr. Edward Palmer, Feb. i— Apr. 9, 1907 as

his no. 98 (Type in herb. Field Museum cat. no. 217,435),

Chamaesyce Standleyi sp. nov.

Annual, prostrate, finely pilose. Stems many, from a thickened root-

stalk; branches densely pilose, short, each subtended by a pair of large

leaves; branchlets very short. Inflorescence solitary in the axils of the

branchlet leaves. Leaves strongly inaequilateral, ovate, 3 x 4—5 x 10

mm., nearly glabrous, cordate, blunt, lightly crenate-dentate more pro-

nounced at the rounded apex; petioles short (.8mm.); stipules linear

entire. Involucres cylindro-turbinate on a very short peduncle with

bract-like leaflets at the base, densely pilose without and within;

lobes triangular, long-ciliate; sulcus narrow, about half the depth of the

involucral tube, fundus unoccupied; glands transverse, narrowly scutelli-

form and somewhat plicate; appendages white, rounded, entire, very

narrow on the lower and somewhat broader on the upper pair of glands;

male flowers few, very short pedicelled and inserted in a ring at the

base of the tube, not as long as the pedicel of the female flower; glabrous;

female flower short pedicelled; ovary obpyriform, pilose; styles long,

bifurcate at the apex. Capsule pilose, deeply tricoccous; seeds ashen,

ovoid-quadrangular, blunt, .9 x. 4mm., the angles sharp and somewhat

included by the ridges; facets marked by 3-4 often incomplete transverse

ridges.

Near Ch. thymifoHa (Burm.).

Only known from the vicinity of Acaponeta, Tepic, Mexico, where it

was collected by Rose, Standley b' Rose, Apr. 10, 1910, no. 14342 (Type in

U. S. National Herbarium cat. no. 637,211).

April, 1916. Euphorbiace^ — Millspaugh 405

Chamaesyce sulfurea sp. no v.

Annual, prostrate-rosulate, siilphur color when dried, glabrous.

Root short; stems many, radiating from the rootstalk, thick, terete;

branches and branchlets many, dichotomous. Inflorescence solitary in

the leaf axils throughout the plant. Leaves ovate-lanceolate, inaequi-

lateral, somewhat falcate, 5x3-11x7 mm., the midrib prominent

beneath, base unequally-cordate, apex acute, margin entire, somewhat

thickened and revolute; petioles about one-quarter the length of the

blade; stipules lacerate-fimbriate. Involucres globular, 5 -columnar,

glabrous; peduncle two-thirds the length of the tube; involucral lobes

deltoid, truncate, 3-toothed at the apex; sulcus shallow, rounded, unoc-

cupied; glands large, stipitate, scutelliform; appendages none; bracteoles

numerous, ligulate, interspersed with 5, thin, lanceolate, fimbriate,

ciliate petaloid rudiments; stamens few, filaments short, glabrous;

female flower long-coliminar-pedicellate, glabrous; ovary smooth, styles

clustered in an erect close mass nearly as large as the ovary itself,

styles thick, clavellate, approximate, bifurcate to the middle. Capstile

strongly tricoccous, the carpels smooth, line of dehiscence strongly

marked; seeds white, 1.5 x i mm., dorsal angle prominent, the whole

surface beautifully sculptured into short, rounded, high, broken trans-

verse ridges appearing like a miniature white cluster of earthworm casts.

Near Ch. ocellata from which the seeds readily differentiate it.

Type station Butte Co., California, on hills east of Chico, near Big

Chico Creek, September 16, 1913, A. A. Heller 11 140 (Type in herb.

Field Museum cat. no. 411,411). Also collected at or near the type

station by H. M. Hall, July, 1914, 9759-

Chamaesyce Gooddingii sp. nov.

Glabrous, prostrate, annual, reddish-green in general color, with a

mass of wiry stems and branches from the somewhat thickened root-

stalk. Inflorescence solitary in the terminal axils. Leaves ovate,

obtuse, 4 X 2-7 X 5 mm. palmately 3-nerved, the midvein prominent

beneath, unequally cordate, margin entire; petioles about one-quarter

the length of the blade; stipules: the lower filiform, entire, the upper

ligulate and often few-lacerate at the apex. Involucres turbinate,

glabrous, peduncles about one-half the length of the tube; lobes triangu-

lar, apiciilate, the margins blunt-ciliate; sulcus shallow, its fundus oc-

cupied by a narrow, lanceolate fiifth lobe; glands stipitate, transversely

narrow-scutelliform, the outer edge crenate-dentate to the appearance of

an appendage; bracteoles none; petaloid rudiments flabelliform, many-

fimbriate; stamens few, filaments long, glabrous; female flowers long-

pedicelled, glabrous, styles divergent, bilobate at the apex. Capsule

4o6 Field Museum of Natural History — Botany, Vol. II

glabrous, strongly tricoccous, the carpels rounded-keeled and minutely

white-punctate; seeds white, .gx .5 mm., elongated ovoid-quandrangular,

angles rounded, the dorsal prominent; facets marked medially with two

longitudinal lines of short, rounded, inconspicuous, irregular, transverse

rugae.

Near Ch. sulfurea from which its seed readily differentiate it.

Type locality Lee Canyon, Charleston Moimtains, in limestone at

8000 ft. alt., Clark Co., Nevada, A. A. Heller 11058 (Type in herb.

Field Musetmi cat. no. 411,087); previously gathered by Leslie N.

Goodding, in sandy washes at Las Vegas, Nevada, in 1907, No. 2282.

Chamaesyce aureola sp. no v.

An erect, or prostrate, pilose annual (?) with a ligneous root from

which spreads a dense mass of terete, divaricate branches and branchlets.

Inflorescence solitary, terminal and upperaxillary. Leaves thick,

strongly inaequilateral, ovate, obtuse, 2-4 x 1.5-2 mm., densely pilose,

cordate, entire; petioles less than one-half the length of the blade;

stipules: the lower deltoid, the upper filiform, those of the upper surface

with a flat, purplish gland at the base. Involucres turbinate, the throat

densely pilose; peduncle about one-half the length of the tube; tube

densely pilose without and within; lobes deltoid, pilose; sulcus V-shaped;

glands transverse, oblong, reddish-brown, fiat and but little cupped;

appendages large, white or creamy, ovate, nearly entire; bracteoles

many, ligulate, glabrous; stamens few, filaments glabrous, the joint

close to the anther base; female pedicel thick, pilose; ovary pilose;

styles 3, bifurcate to the middle, the branches divaricate and not sensibly

enlarged at their stigmatic apices. Capsule strongly tricoccous, densely

pilose; seeds smooth, white, creamy- white or sage-color, elongate-ovate,

1.2 X .6 mm., the dorsal angle prominent, 4-angled at the base, pointed

at the apex, the facets smooth and showing but a few slight indications of

scattered pits.

Near Ch. polycarpa and Ch. vestita from each of which the characters

readily distinguish it.

So far seen only in a series of specimens collected at Azusa, Los

Angeles Co., California, at an elevation of 800 ft. Huron H. Smith 4933

(Type in herb. Field Museimi cat. no. 389,282).

Chamaesyce prostrata (Ait.) Small Fl. SE. U. S. 713, 1333. 1903.

A species of wide distribution misinterpreted in previous Yucatan

publications of species as E. rhytisperma and serpyllifolia on account of

variation from the type form.

The species is represented in the Yucatan Flora by Schoti g6ya from

Merida where it was gathered in a mass of Ch. hirta; Millspaugh 27

April, 1916. Euphorbiace^ — Millspaugh 407

(1887), also from Merida; Gaumer 254 from cultivated ground at Izamal,

460 from stone walls at the same place, and on waste ground at Tekax,

1123,

Chamaesyce rutilis Millsp. Field Mus. Bot. 2:385. 1914-

This species of Guatemala and Honduras has turned up in the

Yucatan region. The type is Chas. C. Deam, 6i8g, Field Mus. cat. no.

285,111 from Fiscal, Guatemala, alt. 3700 ft.

The Yucatan localities are: Chaltumha Road, Sitilpech Road,

Gaumer pjS, gjg.

Chamaesyce vilHfera (Scheele) Small Fl. SE. U. S. 712, 1333. 1903.

The previously known range of this striking species, Texas to Orizaba,

Mexico, is extended farther south by a number of specimens collected

by Dr. Gaumer at Buena Vista Xbac and Chichankanab, Yucatan, 1103,

1 186, 222g.

Chamaesyce jmcatanensis sp. nov.

Rosulate-prostrate from a slender annual root; stem and branches

filiform, pilose. Inflorescence solitary in the axils of the upper leaves.

Leaves inaequilateral, 5-7 x 2-4 mm., oblong-lanceolate, strongly obli-

que at the base, acute, the margin distantly serrate; petioles about imm.

long; stipules represented below by a somewhat denser mass of the stem

hairs, above by a scale-like, waxy gland at the base of the petiole. In-

volucres tubular-campanidate, sessile or apparently so, pilose without

glabrous within; lobes represented by clusters of hairs except where

flanking the deep, round-based sulcus where they are triangular, acute;

glands bright-green, scutelliform, appendages white, unequal, about

twice the size of the glands, ovate, unequally crenate-margined; brac-

teoles none; male pedicels 3-5; female pedicel about the length of the

ovary; styles 3, bifurcate at the upper third; ovary pilose. Capsule

pilose, ovoid, deeply sulcate; seed pinkish-ashen, .8x .5 mm., sharply

angled, the facets marked by irregular and broken transverse ridges.

Near Ch. cozumelensis.

Progreso, Yucatan, on the rocky plain south of the lagoon, Mills-

paugh i6g6, March 5, 1899. Type in herb Field Mus. cat. no. 61,696.

Erroneously referred to Ch. Karwinskyi (Boiss.) {E. Karwinskyi Boiss.)

in Field Mus. Bot. 2 :65.

The other North American species of this genus not previously trans-

ferred to it are :

Chamaesyce acuta (Engelm)

Euphorbia acuta Engelm. Mex. Bound. 189.

4o8 Field Museum of Natural History — Botany, Vol. II

Chamaesyce albescens (Urban)

Euphorbia portoricensis albescens Urban Symb. Antill. i '.Z2>9-

Chamaesyce ammatotricha (Boiss.)

Euphorbia ammatotricha Boiss. Cent. Euph. lo.

Chamaesyce Andromedae (Millsp.)

Euphorbia Andromedae Millsp. Field Mus. Bot. 2:63.

Chamaesyce anychioides (Boiss.)

Euphorbia anychioides Boiss. Cent. Euph. 12.

Chamaesyce arenicola (Parish)

Euphorbia arenicola Parish Erythea 7:93.

Euphorbia cuspidata Engelm, in herb, non Bertol.

Chamaesyce astyla (Engelm.)

Euphorbia astyla Engelm. Boiss. DC. Prodr. 15:40.

Chamaesyce Balbisii (Boiss.)

Euphorbia Balbisii Boiss. Cent. Euph. 11.

Chamaesyce bartolomaei (Greene)

Euphorbia bartolomaei Greene Pittonia 1:290.

Chamaesyce Brandegeei (Millsp.)

Euphorbia Brandegeei Millsp. Proc. Calif. Acad. ser. 2, 2:226.

Chamaesyce bryophylla (Donn-Sm.)

Euphorbia bryophylla Donnell-Smith Bot. Gaz. 56:62.

Chamaesyce capitellata (Engelm.)

Euphorbia capitellata Engelm. Mex. Bound. 2:188.

Chamaesyce carmenensis (Rose)

Euphorbia carmenensis Rose Contr. U. S. Nat. Herb. 1:133.

Chamaesyce centmiculoides (Kth.)

Euphorbia centunculoides HBK. Nov. Gen. 2:41.

Chamaesyce chalicophila (Wetherb.)

Euphorbia chalicophila Wetherb. Proc. Am. Acad. 45:426.

Chamaesyce chamaecaula (Wetherb.)

Euphorbia chamaecaula Wetherb. idem.

Chamaesyce conjuncta (Millsp.)

Euphorbia conjuncta Millsp. Proc. Calif. Acad. ser. 2, 2:227.

Chamaesyce consanguinea (Engelm.)

Euphorbia consanguinea Engelm. Mex. Bound. 187.

Chamaesyce crassinodis (Urban)

Euphorbia crassinodis Urban Symb. Antill. i :34o.

Chamaesyce cumbrae (Boiss.)

Euphorbia cumbrae Boiss. Cent. Euph. i6r.

i

April, 1916. Euphorbiace/E — Millspaugh 409

Chamaesyce Deppeana (Boiss.)

Euphorbia Deppeana Boiss. Cent. Euph. 6.

Euphorbia Anthonyi Brandegee Erythea 7:7.

Euphorbia clarionensis Brandegee idem.

Although Deppe remarks "in California" he must have collected the

plant on some one of the out islands near the California coast. The

species has not been found on the mainland.

Chamaesyce dorsiventralis (Urban)

Euphorbia dorsiventralis Urban Symb. Antill. 5:391.

Chamaesyce floribunda (Engelm.)

Euphorbia floribunda Engelm. Boiss. DC. Prodr. 15:39.

Chamaesyce florida (Engelm.)

Euphorbia florida Engelm. Mex. Bound. 189.

Chamaesyce fruticosa (Engelm.)

Euphorbia fruticosa Engelm. Boiss. DC. Prodr. 15:38,

Chamaesyce Garkeana (Boiss.)

Euphorbia Garkeana Boiss. DC. Prodr. 15:38.

Chamaesyce glyptosperma (Engelm.) Small Fl. SE. U. S. 712; 1333.

Euphorbia Greenei Millsp. Pittonia 2 :88,

Chamaesyce aequata Lun. Am. Midi. Nat. 1:204.

Chamaesyce aequata claudicans Lun. ibid 205.

Chamaesyce glyptosperma integrata Lim. ibid 3:142.

Chamaesyce gracillima (Wats.)

Euphorbia gracillima Wats. Proc. Am. Acad. 21:438.

Chamaesyce grisea (Engelm.)

Euphorbia grisea Engelm.. Boiss. DC. Prodr. 15:41.

Chamaesyce gjrmnadenia (Urban)

Euphorbia gymnadenia Urban Symb. Antill. 5:390.

Chamaesyce Heraldiana nom. nov.

Euphorbia glaberrima Klotz. Seem. Bot. Herald. 276, non Koch.

Chamaesyce hirtula (Engelm.)

Euphorbia hirtula Engelm. Wats. Bot. Calif. 2:74.

Chamaesyce incerta (Brandegee)

Euphorbia incerta Brandeg. Proc. Calif. Acad. ser. 2, 3:171.

Chamaesyce interaxillaris (Fern.)

Euphorbia interaxillaris Femald Proc. Am. Acad. 36:495.

Chamaesyce intennixta (Wats.)

Euphorbia intermixta Watson Proc. Am. Acad. 24:74.

4IO Field Museum of Natural History — Botany, Vol. II

Chamaesyce involuta (Millsp.)

Euphorbia involuta Millsp. Proc. Calif. Acad, ser, 2, 2:227 et 3:170.

Chamaesyce Jonesii (Millsp.)

Euphorbia Jonesii Millsp. Pittonia 2 :89.

Chamaesyce leucantha (Kl. & Gke.)

Anisophyllum leucanthiim Id. & Gke. Tricocc. 27.

Chamaesyce leucophylla (Bth.)

Euphorbia leucophylla Bentham Bot. Sulph. 50.

Euphorbia velutina Greene Biill. Calif. Acad, ser, 2, 5:57.

Chamaesyce liliputiana (Wright)

Euphorbia liliputiana Wright Urban Symb. Antill. 5:390.

Euphorbia minutula Boiss. DC. Prodr. 15:1263.

Chamaesyce linearis (Retz.)

Euphorbia linearis Retz. Obs. 3:32.

Euphorbia ariiculata Aubl. PL Gui. i :48o.

Chamaesyce lineata (Wats.)

Euphorbia lineata Wats. Proc. Am. Acad. 21:454.

Chamaesyce longeramosa (Wats.)

Euphorbia longeramosa Watson Proc. Am. Acad. 25:161.

Chamaesyce luisensis nom. nov.

Euphorbia tomentella Engelm. Boiss. DC. Prodr. 15:32,

non Zipp. ex Span, in Linnaea 15:350.

Chamaesyce magdalenae (Benth.)

Euphorbia magdalenae Bentham Bot. Sulph. 50.

Chamaesyce melanadenia (Torrey)

Euphorbia melanadenia Torr. Pacif. R. R. Exped. 4-'i35-

Euphorbia polycarpa vestita Wats. Bot. Calif. 2:73.

Chamaesyce Mendezii (Boiss.)

Euphorbia Mendezii Boiss. Cent. Euph. 15.

Chamiaesyce multinodis (Urban)

Euphorbia multinodis Urban S>Tmb. Antill. 1:341.

Chamaesyce myrtillifoUa (L.)

Euphorbia myrtillifoUa Linn, Syst. ed. X:io48.

Chamaesyce occidentalis (Drew)

Euphorbia occidentalis Drew Bull. Torr. Club 16:152.

Chamaesyce ocellata (Dur. & Hilg.)

Euphorbia ocellata Dur. & Hilg. Pacif. R. R. Rep. V:5:i5.

Chamaesyce paucipila (Urban)

Euphorbia paucipila Urban Symb. Antill. 5:389.

April, 1916. Euphorbiace^ — Millspaugh 411

Chamaesyce petrina (Wats.)

Euphorbia petrina Watson Proc. Am. Acad. 24:75.

Chamaesyce picachensis (Brandeg.)

Euphorbia picachensis Brandegee Univ. Calif. Bot. 6:185.

Chamaesyce pileoides (Millsp.)

Euphorbia pileoides Millsp. Field Mus. Bot. 2:62.

Chamaesyce podadenia (Boiss.)

Euphorbia podadenia Boiss. DC. Prodr. 15:40.

Chamaesyce polycarpa (Benth.)

Euphrobia polycarpa Bentham Bot. Sulph. 50.

Chamaesyce Pondii (Millsp.)

Euphorbia Pondii Millsp. Contrib. U. S. Natl. Herb. 1:12.

Chamaesyce portulana (Wats.)

Euphorbia portulana Watson Proc. Am. Acad. 24:75.

Chamaesyce pseudoserpyllifolia (Millsp.)

Euphorbia psetidoserpyllifolia Millsp. Pittonia 2 187.

Chamaesyce puberula (Fern.)

Euphorbia puberula Fernald Proc. Am. Acad. ser. 2, 36:494.

Chamaesyce purissimana (Millsp.)

Euphorbia purissimana Millsp. Proc. Calif. Acad. ser. 2, 2:225.

Chamaesyce pycnanthema (Engelm.)

Euphorbia pycnanthema Engelm. Max. Bound. 2:188.

Chamaesyce radicans (Moric.)

Euphorbia radicans Moric. in Berland. PL Exsic.

Euphorbia serpens radicans Engelm. Boiss. DC. Prodr. 15:30.

Chamaesyce radioloides (Boiss.)

Euphorbia radioloides Boiss. DC. Prodr. 15:45.

Chamaesyce ramosa (Seaton)

Euphorbia ramosa Seaton Proc. Am. Acad. ser. 2, 28:121.

Chamaesyce Rattanii (Wats.)

Euphorbia Rattanii Watson Proc. Am. Acad. 20:272.

Chamaesyce rubrospenna (Lotsy)

Euphorbia rubrosperma Lotsy Bot. Gaz. 20:349.

Chamaesyce Rusbyi (Greene)

Euphorbia Rusbyi Greene Bull. Calif. Acad. 57.

Chamaesyce scopulorum (Brandeg.)

Euphorbia scopulorum Brandegee Univ. Calif. Bot. 4:184.

Chamaesyce Seleri (Donn-Sm.)

Euphorbia Seleri Donn-Smith Bot. Gaz. 27:441.

412 Field Museum of Natural History — Botany, Vol. II

Chamaesyce thymifolia (Linn.)

Euphorbia thymifolia Linn. Sp. PI. 454.

Chamaesyce tomentulosa (Wats.)

Euphorbia tomentulosa Watson Proc. Am. Acad. 22:476.

Chamaesyce tonsita nom. nov.

Euphorbia polycarpa hirtella Boiss. DC. Prodr. 15:44, non E. hirtella

Boiss. Cent. Euph. 7.

Chamaesyce polycarpa hirtella Millsp. Parish Cat. PI. Salton Sink 6.

Chamaesyce Torralbasii (Urban)

Euphorbia Torralbasii Urban Sjnnb. Antill. i :340.

Chamaesyce trachysperma (Engelm.)

Euphorbia trachysperma Engelm. Mex. Bound. 2:189.

Chamaesyce Turpini (Boiss.)

Euphorbia Turpini Boiss. Cent. Euph. 12.

Chamaesyce imibellulata (Engelm.)

Euphorbia umbellulata Engelm. Boiss. DC. Prodr. 15:40.

Chamaesyce velleriflora (Kl. & Gke.)

Anisophyllum velleriflorum Kl. & Gke. Tricocc. 28.

Euphorbia velleriflora Boiss. DC. Prodr. 15:40.

Chamaesyce velligera (Schaur.)

Euphorbia velligera Schaur. in Linnea 20:728.

Chamaesyce vestita (Boiss.)

Euphorbia vestita Boiss. Cent. Euph. 7.

Chamaesyce villosior (Greenm.)

Euphorbia villosior Greenman Proc. Am. Acad. ser. 2, 32:297.

Chamaesyce Urbanii nom. nov.

Euphorbia villosula Urban Symb. Antill. 1:340 (1899),

non Pax Bot. Yahrb. 19:118 (1894).

Chamaesyce Watsoni (Millsp.)

Euphorbia Watsoni Millsp. Zoe i :347.

Eumecanthus Kl. & Gke. Monat. Akad. Berl. 1859:248.

Leaves aequilateral, usually sparse below, the upper opposite;

inflorescence solitary or cymose; bracteoles obsolete; seeds ovoid-glob-

ose, deeply and regularly honeycomb-pitted each pit with a secondary

pit or papule in its fundus.

Type species: Euphorbia ariensis HBK.

Leptopus Kl. & Gke. ibid 249, non Decne.

Adenopetalum Kl. & Gke. ibid 250, non Turcz.

April, 1916. EuPHORBiACEiE — Millspaugh 413

Eiunecanthus Armourii.

Euphorbia Armourii Millsp. Field Mus. Bot. 1:28. 1895.

The range of this species is Cozumel Island and the main land of

Yucatan from Merida to Izamal, San Anselmo, Chichan Itza and Buena

Vista Xbac. Schoti 76; Millspaugh 108, ijdg, 1570; Gamner Q75, 1821;

Seler 3927, 4012; Goldman 536.

Eumecanthus astroites (Fisch. & Mey.).

Euphorbia astroites F. & Mey. Anim. Ind. Sem. Petrop. 1845,

Ann. Soc. Nat. ser. 3, 5:371.

Euphorbia astroites heterappendiculata Millsp. Field Mus. Bot. i :28.

1895.

The range of this species is: Mexico at Tampocoala, Karwinsky;

Izamal, Millspaugh 64, Gaumer 521; and Guatemala, Kellerman 8038.

Eumecanthus gramineus (Jacq.) comb. nov.

Euphorbia graminea Jacq. Stirp. Amer. 151. 1763.

This species has a broad distribution from Chihuahua, Mexico,

southward to U. S. Colombia and Ecuador. In Yucatan it has been re-

ttmied from Calotmul, Izamal, Tekax, Temax, Yaxcab and Chichan-

kanab.

Eumecanthus xbacensis.

Euphorbia xbacensis Millsp. Field Mus. Bot. 1:374. 1898.

Only known from the type station, Buena Vista Xbac, Yucatan,

Gaumer 1108, "rare."

The other North American species are:

Eumecanthus ariensis (Kth.) Kl. & Gke. Tricocc. 42. 1859.

Euphorbia ariensis Kunth. HBK. Nov. Gen. 2:46. 181 7,

Eumecanthus Benthamianus Kl. & Gke. idem.

Eumecanthus adiantoides (Lam.)

Euphorbia adiantoides Lam. Encyc, 2:422.

Leptopus Hartwegii Kl. & Gke. Tricocc. 46.

Eumecanthus Bamesii

Adenopetalum Bamesii Millsp. Field Mus. Bot. 2:377.

Eumecanthus bifiurcatus (Engelm.)

Euphorbia bifurcata Engelm. Mex. Bound. 2:190.

Eumecanthus boerhaavifolius (Boiss.)

Euphorbia boerhaavifolia Boiss. DC. Prodr. 15:54.

Eimaecanthus bracteatus (Kl. & Gke.)

Adenopetalum bracteatum Kl. & Gke. Tricocc. 48.

Euphorbia scabrella Boiss. DC. Prodr. 15:55.

414 Field Museum of Natural History — Botany, Vol. II

Eumecanthus delicatulus (Boiss.)

Euphorbia delicatula Boiss. Cent. Euph. 19.

Eumecanthus dioscoreoides (Boiss.)

Euphorbia dioscoreoides Boiss. Cent. Euph. 22.

Eumecanthus discolor (Boiss.)

Euphorbia discolor Boiss. DC. Prodr. 15:54.

Eumecanthus Francoanus (Boiss.)

Euphorbia Francoana Boiss. Cent. Euph. 22.

Eumecanthus Hoffmanni (Kl. & Gke.)

Adenopetalum Hoffmanni Kl. & Gke. Tricocc. 47.

Eumecanthus digitatus (Wats.)

Euphorbia digitata Watson Proc. Am. Acad. 26:146.

Eumecanthus calcicolus (Fern.)

Euphorbia calcicola Femald Proc. Am. Acad. ser. 2, 36:496.

Eumecanthus chiapensis (Brandeg.)

Euphorbia chiapensis Brandegee Univ. Calif. Bot. 6:54.

Euphorbia tetradenia Brandegee exsic. distrib.

Eumecanthus cofradianus (Brandeg.)

Euphorbia cofradiana Brandegee Zoe 5:207.

Eumecanthus colimae (Rose)

Euphorbia colimae Rose Contrib. U. S. Natl. Herb. 1:356.

Etunecanthus guadalajaranus (Wats.)

Euphorbia guadalajarana Watson Proc. Am. Acad. 22:449.

Eumecanthus humayensis (Brandeg.)

Euphorbia humayensis Brandegee Zoe 5:208.

Eumecanthus latericolor (Brandeg.)

Euphorbia latericolor Brandegee Univ. Calif. Bot. 4:377.

Eumecanthus mexicanus (Kl. & Gke.)

Adenopetalum tnexicanus Kl. & Gke. Tricocc. 50.

Eumecanthus microappendiculatus (Lotsy)

Euphorbia microappendiculatum Lotsy Bot. Gaz. 20:349.

Eumecanthus monanthus (Wr.)

Euphorbia monantha Wright PI. Cub. Griseb. 1866.

Eumecanthus multisetus (Bth.)

Euphorbia multiseta Benth. PI. Hartw. 51.

Eumecanthus muscicolus (Fern.)

Euphorbia muscicola Femald Proc. Am. Acad. 36:495.

Eumecanthus ocymoideus (L.)

Euphorbia ocymoidea Linn. Sp. PI. 453.

April, 1916. Euphorbiace^ — Millspaugh 415

Eumecanthus pedunculosus (A. Rich.)

Euphorbia pedunculosa A. Rich. Hist. Cuba 11:198.

Eumecanthus physalifolius (Boiss.)

Euphorbia physalijolia Boiss. Cent. Euph. 19.

Eumecanthus pubescens (Kl. & Gke.)

Adenopetalum pubescens Kl. & Gke. Tricocc. 49.

Adenopetalum irasuense Kl. & Gke. ibid. 50.

Eumecanthus segoviensis (Boiss.)

Euphorbia segoviensis Boiss. DC. Prodr. 15:58.

Eumecanthus sinaloensis (Brandg.)

Euphorbia sinaloensis Brandegee Zoe. 5:208.

Eumecanthus subpeltatus (Wats.)

Euphorbia subpeltata Watson Proc. Am. Acad. 25:146.

Eumecanthus subreniforme (Wats.)

Euphorbia subreniforme Watson Proc. Am. Acad. 21:438.

Eumecanthus subsinuatus (Boiss.)

Euphorbia graminea subsinuata Boiss. DC. Prodr. 15:54.

Eimaecanthus tenerus (Wats.)

Euphorbia tenera Watson Proc. Am. Acad. 18:150.

Eumecanthus triphyllus Kl. & Gke. Tricocc. 43.

Euphorbia triphylla Willd. Herb. 9316.

Euphorbia scabrella Boiss. DC. Prodr. 15:55.

Eumecanthus imabrosus (Bertero)

Euphorbia umbrosa Bertero Spr. Syst. 3:791.

Eumecanthus violaceus (Greenm.)

Euphorbia violacea Greenman Proc. Am. Acad. ser. 2, 33 :48o.

Eumecanthus xalapensis (Kth.)

Euphorbia xalapensis HBK. Nov. Gen. 2 :48

Eumecanthus zierioides (Boiss.)

Euphorbia zierioides Boiss. DC. Prodr. 15:58.

Aklema Rafin. Fl. Tell. 4:114. 1836-1838.

Branches articulate; leaves aequilateral, temate or verticillate;

stipules glandular; inflorescence in axillary and terminal cymes, corymbs

or panicles; bracteoles numerous, plumose; seeds ovoid-globose, shal-

lowly open and regiilar pitted with no secondary pits.

Type species: Euphorbia nudiflora Jacq.

Euphorbia Linn. Sp. PI. 453, in part. 1753.

Alectoroctonum Schlecht. in Linn. 19:252. 1847.

Peccana Rafin. Sylv. Tell. 114. 1838.

4i6 Field Museum of Natural History — Botany, Vol. II

Aklema Gaumeri

Euphorbia Gaumeri Millsp. Field Mus. Bot. 1:372.

The only known range of this species is Yucatan, at San Anselmo

and Buena Vista Xbac, Gaumer iojq, loyj, 1443.

Aklema Mayana

Euphorbia Mayana Millsp. Field Mus. Bot. i :304.

Only known from Yucatan, at Izamal and Buena Vista Xbac

Gaumer 302, lojg.

The other North American species are:

Aklema adinophylla (Donn-Sm.)

Euphorbia adinophylla Donn-Smith Bot. Gaz. 47:261.

Aklema apocynoides (Kl.)

Euphorbia apocynoides Klotzsch Seem. Bot. Herald 99.

Aklema colletioides (Bth.)

Euphorbia colletioides Benth. Stdph. Voy. 163.

Aklema comonduana

Euphorbia comonduana Millsp. Proc. Calif. Acad. ser. 2, 2:229.

Aklema cotiiilfolia (L.)

Euphorbia cotinifolia Linn. Sp. PI. 453.

Aklema elliptica (Kl. & Gke.)

Adenopetalum ellipticum Kl. & Gke. Tricocc. 50.

Euphorbia saccharata Boiss. Cent. Euph. 18.

Aklema Friderichthalii (Boiss.)

Euphorbia Friderichthalii Boiss. DC. Prodr. 15:61.

Aklema ligustrina (Boiss.)

Euphorbia ligustrina Boiss. Cent. Euph. 22.

Aklema Nelsonii

Euphorbia Nelsonii Millsp. Bot. Gaz. 26:268.

Aklema nudiflora (Jacq.) Rafin. Fl. Tell. 4:114.

Euphorbia nudiflora Jacq. Coll. 3:180.

Aklema oaxacana (R. & G.)

Euphorbia oaxacana Robn. & Greenm. Proc. Am. Acad. 32:37.

Aklema ovata (Schlecht.)

Alectoroctonum ovatum Schlecht. in Linn. 19:252.

Euphorbia Schlechtendahlii Boiss. Cent. Euph. 18.

Aklema peganoides (Boiss.)

Euphorbia peganoides Boiss. Cent. Euph. 22.

Aklema petiolare (Sims) MiUsp. Ann. Mo. Bot. Gard. 2:43. 1915.

Euphorbia petiolaris Sims. Bot. Mag. t. 883.

April, 1916. Euphokbiace^e — Millspaugh 417

Aklema plicata (Wats.)

Euphorbia plicata Watson Proc. Am. Acad. 21:438.

Aklema Scotana (Schlecht.)

Alectoroctonum Scotanum Schlecht. in Linn. 19:252.

Euphorbia Scotana Boiss. DC. Prodr. 15:60.

Aklema tricolor (Greenm.)

Euphorbia tricolor Greenm. Proc. Am. Acad. 33:479.

Aklema Xanti (Engelm.)

Euphorbia Xanti Engelm. Boiss. DC. Prodr. 15:62.

Euphorbia gymnoclada Engelm. Proc. Am. Acad. 5:171, non Boiss.

Aklema yavalquahuitl (Boiss.)

Alectoroctonum yavalquahuitl Schlecht. in Linn. 19:252.

Acalypha flagellata sp. nov.

A dioecious shrub, 2-5 meters high, glabrous or nearly so, with terete,

pithy branches, large leaves (7.5 x 12 cm.) and very long spikes (15-35

cm.).

Stipules leafy, narrowly ovate-lanceolate, serrate, apiculate, 1-2 cm.

long; petioles 6-7 cm. long; blade palmately 5-veined, ovate, acimiinate,

thin, minutely wrinkle-pitted in drying, crenate-dentate, each tooth

mucronate. Infloresence in long, simple, lash-like, axillary spikes often

in pairs on the male shrubs though generally single, rarely one monoecious

spike appears, this always on the female shrub. Female flowers single,

on a long, filamentous pedicel (8-12 mm.); pedicel bibracteate, pilose;

calyx 4-parted the lobes linear-lanceolate, ciliate, acute; ovary hairy and

stalked- tuberculate; stylar column glanduliferous, turbinate, the upper

portion cut into three lobes from each of which issues a fascicle of six

long, filiform, transparent stigmas. Male flowers densely fasciculate

on slender, cylindrical spikes, very short pedicellate; sepals 4, scaphoid,

minute, caducous; stamens 8, filaments ligulate, ciliate. Capsule 5 mm.

diam. deeply tricoccous the cocci globular, strongly marked by the line

of dehiscence, scurfy and stalked-glanduliferous-tuberculate beneath;

seed red-brown, globose, apiculate, 1.2 mm. diameter, minutely papil-

late-carunculate, the surface minutely puncticulate.

Type station Buena Vista Xbac, Yucatan, Gaunter, September 1896,

iioy (Type in herb. Field Museum, cat. no. 438,224). Also gathered by

Dr. Gaumer at Chichankanab 2iy8, 21'jg.

Acaljrpha simplicissima sp. nov.

An erect, simple, slender annual about 4.5 cm. high. Stem terete,

crispidulous-hairy. Petioles filiform about the length of the thin, ovate,

4i8 Field Museum of Natural History — Botany, Vol. II

acute leaves; leaves 3 x 1.5-4 x 2.5 cm., glabrous, palmately 5-nerved at

the rounded base, margin slightly crenate-dentate. Inflorescence axil-

lary, the female flowers on long (3-6 cm.), pedunculate, wiry, 10-18-

bracted, open spikes; the male on a short, rudimentary, capitulate spike

separate in the same axils. Bracts of the female flowers 6-7 mm.

ovate, narrowed to the sessile base, acute, the margin few-serrate,

ciliate. Female flowers usually 3 to the bract, sessile; calyx 3-parted,

lobes narrowly lanceolate; styles 6, fibrillate, about four times the

length of the ovary. Male flowers 10 or more in a dense, pedunculate

head; calyx of four linear lobes with transparent, chaff-like margins.

Capsule strigose-hairy; seed ashen, smooth, ovoid-apiculate, 1.2x1 mm.

Yucatan, at Progreso in a shady coppice. Gaunter 1182 (Type in

herb. Field Museum, cat. no. 438,255), and at Chichankanab, Gaumer

2225.

Croton Gaumeri sp. no v.

Dioecious, fruticose, open stellate-pubescent. Leaves thin, lanceo-

late-acuminate, 3-4.5 X .75-1.50 cm.; petioles one-third the length of the

blade; male shrubs with leaf margins distantly glandulose, on some

individuals these glands become long-stalked though by no means on all

nor on all leaves on any one shrub. Leaves (male) papillate on both

surfaces, the margin generally distantly glandulose and often stalked-

glandular especially near the base, in young leaves both surfaces are

openly stellate-pubescent; stipules triangular, seldom found at the older

leaves; leaves on female shrubs scattered stellate-pubescent above, more

closely and prominently so beneath. Inflorescence terminal, in long,

slender spikes floriferous above, flowers pedicellate, bracts minute, the

male spikes sHghtly pubescent the female decidedly so and with long,

straight hairs mixed with the closely appressed stellate ones; male

flowers: caly:x stellate-hairy, 4-lobed, the lobes ovate, acute, rudimentary

petals 4, lanceolate, stamens about 20, filaments glabrous; female

flowers: pedicels half the length of the calyx, calyic stellate-pubescent,

5-lobed, lobes oblong-lanceolate, acute, margin glandular, rudimentary

petals 5, alternate with the caljrx lobes, narrowly ligulate and tipped

with a globular gland, appearing like stamens, styles 3 divided to the

base, digitately 4-lobed, lobes cylindrical, incurved at the tip. Ripe

capsule about 5 mm. diam., smooth as if varnished and bearing a few

isolated stellate hairs; seed scaraboid, smooth and shining greenish-

brown, 3.5 X 2.8 mm., canincle strongly reniform, thin, waxen.

Yucatan, vicinity of Izamal. Unnumbered specimens collected by

Dr. Gaumer in 1894 (Type in herb. Field Museum cat. no. 187,265).

Two sheets of twigs of male shrubs appear in the series of Dr. Gaumer's

April, 1916. Euphorbiace^ — Millspaugh 419

Izamal collection of 1888 deposited in Kew Herbarium; duplicates of

these in herb. Field Museum bear its cat. nos. 181,499 ^nd 181,500.

Croton glandulosepalus sp. nov.

A tall, white-barked shrub with long, terminal spikes and thin,

ovate-lanceolate leaves clustered toward the tips of the branchlets

leaving the branches bare. Leaves ovate-lanceolate, sparingly ap-

pressed-stellate, acute to aciuninate, apiculate, 4-6 x 2-3 cm., 3-nerved

at the base, both surfaces dotted with scattering, fine, slender, stellate

hairs which nearly disappear when the leaves are fully mature; petioles

slender, about one-third the length of the blade, puberulous; stipules

aristate, about 5 mm. long. Inflorescence monoecious, terminal in

elongate, rather openly flowered spikes with large, ovate bracts bear-

ing a number of long-stalked, ciliate glands on the margin. Male

flowers short-pedicellate enclosed by the scaphoidally enveloping bracts,

caly^ 4-lobed, woolly with stellate hairs, lobes ovate, petals 4, thin,

ovate-scaphoid, glabrous or nearly so; stamens 10, filaments short

(about the length of the anthers), glabrous, anthers large, innate. Fe-

male flowers: thick pedicelled and densely white-woolly below; calyx

4-lobed the lobes ovate-lanceolate, sarcous, exteriorly invested with a

dense mass of red, stalked-globular glands and enclosing the pistil

closely; petals small, flabelliform, margin stalk-glandular; ovary densely

white-stellate woolly; styles 3, each 4-cleft to the base, the filamentous

branches incurled at their tips. Capsule and seed unknown.

Yucatan, common on the open plain from Progreso to Merida,

Gaumer 11 54 (Type in herb. Field Musetun cat. no. 438,492). Also re-

turned by Dr. Gatmier from Buena Vista Xbac, 1046 and from Chichan-

kanab 2204.

Croton malvavisciifolius sp. nov.

Shrub with terete, ferrugineous branches, large bi-colorate, irregular-

ly and doubly serrate-dentate leaves, and short monoecious terminal

spikes. Stems rusty stellate-hairy the central ray of the stellae erect

and acicular the base appressed to the bark; stipules ligulate; petioles

somewhat less than one-third the length of the leaf blade. Leaves broad-

ly ovate, 7-14x5-10 cm., acute to acuminate, palmately 7-nerved,

dark-brown, papillate and scattered stellate-hairy above, light-green

and densely felted with stellate hairs beneath, each leaf bearing 2

fimnel-shaped, long, stalked glands at the petiole, base strongly cordate,

apex acute, margin irregularly doubly-serrate, dentate with a stalked,

funnel-shaped gland in the sinus of each of the larger dentations. In-

florescence monoecious, terminal, short, female below male above.

420 Field Museum of Natural History — Botany, Vol. II

densely ferrugino-stellate pubescent. Female flower short-pedicellate,

bicolorate (dark within light without) color and pubescence a counterpart

of that of the leaves; cal3rx lobes 5, spatulate, deeply 3-5-dentate toward

the apex; ovary ovate, rusty-hairy, styles 3 each bifid to the base, the

branches long and cyHndrical, with flattened, incoiled apices. Male

flower bicolorate as in the female, pedicellate; calyx 5-lobed the lobes

ovate, obtuse; petals 5, obovate-spatulate, thin, red-brown; stamens 6,

filaments with a tuft of hairs at the base. Capsule densely stellate-

pubescent, enclosed in the persistent calyx; seed flatly scaraboid, 3x2

mm., caruncle very thin, papyraceous.

Yucatan, at Yot Tzonot, Gaumer ijiq (Type in herb. Field Museum

cat. no. 438,278).

Tragia {Eutragia) yucatanensis sp. nov.

An erect, shrubby climber, i meter high. Stem terete, puberulent,

branches virgate; stipules small, cordate-lanceolate, acute, closely ap-

pressed to the stem; petioles one-third to one-half the length of the leaf

blade; leaves ovate-lanceolate, 3-6 x 2-4 cm., 5-nerved, somewhat

cordate at the base, acuminate, dentate, scattered-hairy on both sur-

faces. Inflorescence in few flowered, slender, short, simple racemes

one-half to three cm. long, inserted opposite the upper leaf petioles, the

female solitary near the base of the raceme, the male few, terminal;

bracts minute, sessile, lanceolate, acute, entire. Male flowers pedicelled;

pedicel about equaling the width of the QolyK., pilose, somewhat thick-

ened below; calyx 3-parted, lobes ovate, acute, glabrous; stamens 3,

filaments turgid-bulbous below; anthers ovate; rudimentary ovary

wanting. Female flowers pedicelled; pedicel about one-half the width

of the calyx; cdlys. segments 6, ovate, acute; ovary 3-celled, densely

acicular-hairy ; style turgid, trifurcate to the middle, the branches tightly

recurved at the tips. Capsule densely invested with long, white, acicu-

lar hairs; seed globose, 2.3 mm. diameter, yellow, mottled in irregular

anastomosing splotches and stippled with minute dots of red-brown.

Yucatan, in woodlands at Chichankanab, Gaumer 2154 (Type in

herb. Field Museum cat. no. 438,347) ; and at San Anselmo, 1931. This

species and Tragia nepetaefolia are called P o p o x by the Mayas.

April, 1916. Alacran Reef — Millspaugh 421

VEGETATION OF ALACRAN REEF

The Alacran Reef forms the northeastemmost danger on the Cam-

peche Bank, in the Gulf of Mexico, 75 miles N. by E. ]4 E. from Sisal

Fort on the Yucatan mainland. The position of Perez Cay, its most

southern islet, is latitude 22°33'36"N.; longitude 89°4i'45"W.

The general form of the reef is semilunar, convex to the NE., the

straight western face trending NNW. >^ W. 14 miles, its greatest width

being 8 miles. The weather, or NE. side, is composed of a compact

mass of coral, dry in many places, over which, on all parts, the sea

breaks with violence. The lee side, similar to all reefs of this character

in these seas, is composed of detached coral heads, easily seen in the

clear, deep water of the bank.

At the SE. extreme of the reef are three small, sandy cays rising

not over 5 ft. high. These are known as Perez, Pajaros and Chica Cays.

Pajaros and Chica lie yi mile apart 800 yds. from the SE. extremity of

the reef, Perez l3dng about a mile westward from them. Between the

eastward pair and Perez there is an excellent reef -harbor for small ves-

sels; formerly 4 fathoms could be carried into this harbor but at the

time of oiur visit it held, in a few places, but a precarious 2 fathoms.

NW. by N., 3 miles from Perez, is a small cay, about 8 feet high,

which we named Allison Island, and about the same distance southward

of the NW. end of the reef is another islet, about 10 feet high, which we

named Utowana Cay, though we were unable to land upon it on account

of sea conditions at the time of our approach.

The Alacran Bank is everywhere so steep-to that there is no safe

anchorage for larger vessels, not even on the lee side, the only clear

landing place is on the inner side of Perez Cay at the mouth of the reef-

harbor mentioned.

The approach to this shoal, when working to windward, requires

more than ordinary attention as the soundings near it do not give suf-

ficient warning and the islets are invisible if the sea be high. As the

Yacht Utowana (which the owner and master Mr. AUison V. Armour

allowed to approach the reef on the voyage of which I had the honor of

being his guest) arrived in the neighborhood, the captain slowed the

vessel down and sent a lookout to the cross trees. Though we proved to

be but about two miles from Allison Island yet nothing could be seen

of the reef until a cloud of frigate-birds* arose indicating its presence.

As the reef lies directly within the sweep of the Gulf Stream in the

youth of its course we judged that it might receive aquavectent seeds

*Fregata aquila (Linn.).

422 Field Museum of Natural History — Botany, Vol. II

^

i/toivcma Cay

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ALACRAIST

HEEF

<^Mlison Isl.

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April, 1916. Alacran Reef — Millspaugh 423

from the east coast of Yucatan, Cozumel Island, and the Caribbean

mainland; and, on that account, desired to record its vegetation at this

time (March, 1899).

At the time of the charting of this reef by the British Admiralty, in

1842, Pajaros and Chica were "bare sand spits devoid of vegetation;"

Perez, the largest cay, and Allison Island, had upon them "grass*

and samphiret only." This record we are boimd to accept as a careful

and comprehensive one for the reason that on account of the dangerous

character of the reef it was essential that it should be accurately de-

scribed, even to its vegetation. Accumulated obser\'^ations from 1842 to

1896 added "brushwood" to the southern cays and "bushes" to Allison

Island, though no traces of bushes were to be found on the latter at the

time of our visit; this indicates one of two facts: either that they had

been removed, even to their roots, by fishermen for firewood, or by

natural erosion. The age of the stunted trees termed "brushwood,"

as I have recorded further on under Siuiana maritima, proves that

"brushwood" was not on Perez in 1842 at the time of the Admiralty

survey.

In searching out the vegetation of the cays a most careful survey

was made. Each cay was minutely examined by our party over every

square foot of its surface, I am certain that no species escaped our at-

tention. A detailed indication of each of the eighteen species fotmd is

given in conjunction with the map.

The discovery, on these islets, of three species new to science, with

the proof that they have evolved within the known and definite period

of 57 years, is a fact impressive as it is important.

Perez Island, the largest cay, rises about 5 feet in height, its

beach being more or less abrupt on the west and gradually sloping on the

east or inner coast line. It is about 2550 feet in length and about 325

feet wide as its broadest point. Its surface is entirely coral sand except

for a small cairn of weathered coral heads as indicated below.

I was informed that a few years previous to our visit a party of men

was left on this cay, by the Mexican Government, w4th material for the

purpose of constructing a beacon. Their supplies gave out and no more

were sent to them. They were finally rescued by a fishing vessel and

brought to the mainland in a dying condition. One died before the

rescue and was buried at the north end of the cay. Several holes in the

cay attested to thejpiteous attempts of these neglected men to secure

*Sporobolus virginicus.

tSesuvium portulacastrum.

424 Field Museum of Natural History — Botany, Vol. II

drinkable water. From the largest of these holes at the northern third

of the islet a mound of weathered coral heads was heaped during its

excavation. This forms the only prominence on the surface of the cay

and is the habitat of a growth of cactus (Opuntia Toona) the seed of

which was doubtless dropped here by some resting bird. In like manner

a seed dropped from an arm of the little wooden cross marking the grave's

head accounts for the only plant of Scaevola Lobelia. The "wooden,

pyramidal framework 30 feet high" erected by this party at the south

end of the islet, mentioned in the U. S. Coast Pilot for 1896, had long

since disappeared as kindling for fishermen's cuddy fires.

The main extent of the surface is densely clothed, about 8 in. deep,

with a level carpet of Sesuvium portulacastnun broken in only three

places by small patches of Sporobolus virginicus associated, in one in-

stance, with Portulaca oleracea; in another with Boerhaavia repens;

and in a third with Flaveria linearis which has scattered in among the

Sesuviimi as mentioned under the consideration of this species. The

whole of the south end is clothed with a nearly pure growth of the Sporo-

bolus in which a few plants of Atriplex cristata have foimd a rooting.

The whole west, or weather, bank is lined with a fringe of Suriana

which exists without the admixture of any other species for the northern

two-thirds of its length; to the southward a few shrubs of Toumefortia

intermingle and still further south six climips of Conocarpus. Between

the Suriana fringe, on the top of the bank, and the wave line of the

narrow strand at the southern third, a scattering growth of the new

Caldle, intermixed further southward with Chamaesyce buxifolia, com-

pletes the flora of the west shore. The interspersed species of the toe

of the stocking-shaped islet, where boobies* evidently ahght during

fishing, were Cenchrus carolinianus, Portulaca oleracea and one individ-

ual each of Tribulus alacranensis and Cyperus brunneus.

For some reason neither the booby nor the frigate-bird, prevalent

on the other cays, nest on this islet. The reason is not apparent to me

tmless mayhap the presence of the complete fringe of shrubbery on the

west shore may prove, in some way, inimical to them.

Pajaros (Bird) Cay, the southeast islet of the shoal, is a low, pure

sand microcosm, rounded to the center, with the eastern or weather

shore line slightly banked and the western, or inner, beach sloping. It is

about 650 X 325 feet in extent.

The distribution of plant species on its surface is in exact duplication

of that on Perez; Cakile and Chamaesyce on the beach line of the

weather shore and no plant life on the marge of the sloping strand.

*Sula cyanops (Sunderval).

The Grave on Perez Island.

A Booby on its Nest Composed entirely of the Stems of tribulus Alacranensis.

Northwest End of Chica Island Carpeted with Sesuvium.

Horizon.

Looking toward Pajaros on the

April, 1916. Alacran Reef — Millspaugh 425

Two shrubs only had secured a footing on this cay, one each of Conocar-

pus and Toumefortia. Scattered amongst the dense growth of Sesuvium

was found a number of clumps of the new Cenchrus, forming its only

habitat, and one climip each of the new Tribulus, Portulaca oleracea

and Atriplex cristata. In the clear sand beyond the Sesuvium at its

northernmost margin was another colony of the new Cenchrus.

Chica (Little) Island is another low, pure sand cay, fusiform in

outline, 575 x 325 feet in extent.

On this islet the disposition of the Sesuvium and Sporobolus areas

is reversed in comparison with the other two cays, while the scattering

other species are interspersed with the Sporobolus colony instead of the

Sesuviiun. In this the clothing of the islet is quite similar to that of the

foot of Perez and shows plainly that it forms a resting place for web-

footed birds. Here the new Tribulus, Atriplex cristata and the Chamae-

syce grow in profuse masses while the new Cakile maintains its charac-

teristic habitat on the weather beach line.

Allison Island, three rmles from the other cays described, differs in

several respects from the other three. First : it lies east and west — the

others essentially north and south; second: its entire coast line is weather

shore; i. e., abrupt and eroded above a narrow strand, except a small

portion of its western extremity which is somewhat spit-like; third:

it is considerably higher (about 8 ft.) and flat Hke a table-land. Its

dimensions are about 1000 x 275 feet.

Notwithstanding the fact that this islet is comparatively large it

nevertheless gives place to but six plant species. Its "grass " and "sam-

phire " colonies are pure, as on the other islets. The largest bird colonies

of all are on this cay, in fact it is almost wholly a nidulation ground.

Boobies appropriate the grass colony and frigate-birds the Sesuvium

tract. It is on this cay that Tribulus alacranensis evolved, its presence

on the other cays being a matter of transplantation through its burs

having adhered to the feet of the booby. The species exists in dense

colonies amongst the Sporobolus, and it is of its ligneous stems and

branches that the boobies build their nests. The only colony of Philox-

erus vermicularis on the cays is here in the Sporobolus, as well as a widely

scattering growth of the Chamaesyce. Again the new Cakile lines

itself along the weather strand but only on the weathermost side.

Utowana Cay, which we sighted but were unable to attain, is the

northernmost islet of the group. Through the glass its surface appeared

very like that of Allison Island. As it lies north and south much

further within the bank of the reef than any of the other cays its vegeta-

426 Field Museum of Natural History — Botany, Vol. II

tion should prove particularly interesting, we were deeply disappointed

that the risk was too great to allow of the yacht being brought near

enough to grant us a landing.

THE PLANT SPECIES

1. Sesuvium portulacastrum (L.) Linn. Syst. ed. X, 1058.

This is by far the prevalent species of the cays and here forms the most

extensive and succulent masses I have ever seen. It clothes the easterly

areas of all the islets with a dense carpet about eight inches thick. Only

a few individuals were in flower at the time of our visit. As the stems

of this plant are fragile; broken pieces long-lived; and as such pieces

put forth strong and viril rootlets in water, I am inclined to place its

dispersional character as bodily aquavectent. It is possible also that

ripe fruits may be transported in like manner. Its characters are strong-

ly against avevectence.

2. Sporobolus virginicus (L.) Kunth. Rev. Gram. 1:67.

The second species in extent on the cays. This grass appears to

spread only where some influence has checked the growth of the Sesuv-

ium, as for instance the tramping about of the birds or the digging of

water-holes and the constructive efforts of the men who built the beacon

structure on the south end of Perez. This is so pronounced a fact that

a glance at the distinguishing colors on the maps shows by the yellow,

for Sporobolus, the location of the three water-holes and the area of

the beacon-site; while the yellow on the maps of the other cays demarks

perfectly the booby nesting areas — always, for some reason westerly

on the islets. Note, by the same token, that the booby sections are

always where the land slopes gently to spit-like extremities.* The booby

never nests near the weather, or abrupt, shore.

From its habitat it is evident that Sporobolus is aquavectent; it has

however only been found, on the Yucatan mainland, in protected situa-

tions near lagoons, whence, if its Alacran soiu*ce is the mainland, its

spikes must first have been blown to the sea before its real transportation

began.

3. Suriana maritima L. Sp. PL 284.

A fringe of low shrubs of this species lines the top of the ''bank"

of the western or weather shore of Perez Island. The growth is pure in

the northern two-thirds of the fringe, the southern third has an inter-

mixture of a few clumps of Toumefortia and, further south, of Conocar-

pus.

* In order that the fledglings may get to the water and back to the nest?

April, 1916. Alacran Reef — Millspaugh 427

In order to check up the record of the Admiralty survey I cut down

the two apparently oldest shrubs and made cross sections of the trunks.*

In so far as the annual rings may determine they proved to be 25 and

30 years old respectively. Should the rings prove a faulty record the

error would be in favor of a shorter period of growth, it is therefore

certain that the shrubs did not exist there at the time of the survey, the

notes of which state: "Grass and samphire only." One shrub, judged

to be not over four years old, grew on the southern shore of Chica.

At the period of ripened fruits the fruiting twigs of this species be-

come quite brittle and, as the plant frequents the immediate sea shore,

these twigs are often broken off by heavy winds and blown into the sea.

That they float away and are later washed ashore on the crests of waves

was apparent in the "wash line" on the weather side of Perez where I

found a large quantity of fruiting twigs newly come ashore. This

leaves no doubt of the species being bodily aquavectent.

4. Cakile alacranensis Millsp. Field Mus. Bot. 2:130.

This new species of the shoal differs from all others known in its

short silique bearing four channelled lines instead of 8 or more (angles

in most species); in its upper joint being globose-apiculate and very

turgid; in its infundibuliform lower joint which is but httle more than a

swelling of the pedicel, and in having its seeds dotted with brownish

punctae. The leaves are yellowish-green, spatulate-lanceolate tapering

to a partly clasping petiolar base, and entire or rarely slightly crenate or

crenate-dentate at the apex.

This species grows upon the north strand of Allison Island; on the

north weather strand of Chica and Pajaros; and on the southern half of

the weather strand of Perez.f While the plants from both Perez and

Pajaros are large fruit producers they have a sickly yellow appearance

compared with the fresh, cool green of those of Chica. It is evident that

the original habitat of this species is either Allison Island, or possibly

unexplored Utowana Cay, as the distribution of the plants on the south-

ern cays is quite apparently more recent.

It appears to me that this species is evolving for the piu-pose of

more highly developed aquavectence. The upper, or floating joint, is

certainly developing far more rapidly than the lower, or fixed, joint of

the fruit : the upper at the expense of the lower.

Distributionally the upper joint of the fruit is aquavectent while the

lower, being fixed upon the rhachis and on that account not adapted to

*These sections are mounted on the herbarium sheets of the species from this

island in the Museum herbariiun.

tThe treatment of Cakile in Field Mus. Bot. 2:43 and 2:128-130 to the contrary

not withsta nding .

428 Field Museum of Natural History — Botany, Vol. II

dispersion, is evidently intended to perpetuate the species only in the

habitat of the parent plant.

5. Chamaesyce buxifolia (Lam.) Small.

This common seaside Euphorbia is found, on the booby rest-strands

only, on all the islets. It does not associate (except on Pajaros) with

the aquavectent Cakile nor with other aquavectent species.

The seed coat of this species swells greatly and becomes mucilag-

inous when moist. This causes the seeds to adhere to the wet webs of

swimming birds when resting along the shore. Thus the plants are

widely distributed on the island strands of the Gulf of Mexico region.

6. Tribulus alacranensis MiUsp. Field Mus. Bot. 2:54.

This new species differs from its probable parent, T. maximus of the

mainland, in its long, heavy, tangled and jointed Ugneous stems and

branches; its mass growth; its larger flowers and smaller fruits; its

4-6-spined carpids; and in its leaves being densely woolly on both sur-

faces. The original habitat* of this species is apparently the Sporo-

bolus colony of Allison Island, where the boobies construct their nests

wholly of its stems and branches.

The dispersional character of the species is avevectent, through the

sharp-spined fruits clinging to the webbed feet of swimming birds.

7. Tournefortia gnaphalodes R. Br. Prod. 496.

This common sea shore shrub of the Antillean region has found a

place of growth amongst the Siuiana shrubs at the southern extension

of the fringe on Perez. One shrub only was just appearing on the south

shore of Pajaros. The specimens appear to differ in no respect from

those of the mainland.

As with Stiriana the fruiting branch tips of this species break off

dtuing high winds and are often blown into the sea, whence they are

drifted to new places of growth. The species is, again like Siuiana

bodily aquavectent in dispersional characters. It is very seldom, if

ever, found on the shores of bays or on shores guarded by partly dry

reefs.

8. Conocarpus erectus Linn. Sp. PI. 147.

A few clumps of this shrub have established themselves amongst

the Suriana bushes at the south end of the fringe on Perez Island, where

the shore being free on the weather edge of the reef, there has accumulated

quite a congregation of wave carried species.

Two of the largest trunks of this species showed, by the armual

rings, a growth of 19 years.

*As Utowana Cay was not explored this statement is open to doubt.

April, 1916. Alack an Reef — Millspaugh 429

From its association on these cays I judge that the fruits are aquavec-

tent. Its growth in no wise gives the appearance of bird transportation.

9. Flaveria linearis Lag. Gen. et Sp. Nov. S3-

A few plants of this species were found near the coral cairn on Perez

Island. A few more were found scattered in the Sesuviimi carpet a short

distance northwestward from the cairn. The species is fairly common

on the coast of the mainland of Yucatan and on the island of Cozimiel.

This dispersion of this species to the Alacran Reef must have been

intestinally avevectent as the seeds have no coma and the position of

the plants on Perez savors highly of resting birds.

10. Portulaca oleracea Linn. Sp. PI. 445.

A few individuals of this species were found scattered amongst

the Sesuvium of Perez and Pajaros cays. It had not yet become im-

planted on the other cays visited.

In my studies of the intimate dispersion of species upon sand islets*

I have fovmd this species only upon inhabited islands and then generally

in areas that were at the time, or had been, more or less cultivated for

some purpose. The position of the plants on Perez and Pajaros in

no way indicate homovectence, though on Perez this might have been

possible. The dispersional indications in regard to this species are not

sufficiently plain to me at this time to permit a distinct statement.

11. Cyperus brunneus Sw. Fl. Ind. Occ. 1:116.

One clump only of this species was found on the cays that on the

southwest end of Perez Island just beyond the Sporobolus colony.

This species is quite a common element of the Antillean strand flora

from the Bahamian Archipelago through to Vera Cruz, Mexico. It

occurs in places all along the Yucatan coast and on the strands of the

island of Mugeres.

The seeds are avevectent per pedis et intestinis.

12. Atriplex cristata H. & B. ex Willd. Sp. PI. 4:959.

A group of a few individuals of this species was found in the Sporobol-

us colony on the south end of Perez and qmte a large cluster in the same

association on Chica. On Pajaros a small group was found in associa-

tion with the Sesuviimi. The species has also been returned from the

Yucatan main coast at Progreso and Silam.

I judge that the fruits are 'avevectent, being transported on the

webbed feet of the booby, and that the cliunp in the Sesuvitmi of Pajaros

came originally from the older implantation on Chica.

*" Flora of the Sand Keys of Florida," Field Museum of Natural History, Botany,

Vol. 2, no. 5.

430 Field Museum of Natural History — Botany, Vol. II

13. Cenchrus carolinianus Walt.

This species* was found only at one spot, that on the south shore of

Perez Island near the clumps of Conocarpus at the edge of the Sporo-

bolus colony at that point. The species has also been returned from

Cozumel Island but not from the Yucatan mainland.

The species is avevectent through the spiny burs clinging to the

webbed feet of the booby.

14. Cenchrus insularis Scribn. Field Mus. Bot. 2:26.

This new species is represented by a few plantst on Pajaros Island

only. These were all in full ripe fruit. That this is the full representa-

tion of so strongly a differentiated species is open to doubt and will so

C. insularis.

C. echinatus

remain until opportunity is had to visit Utowana Cay, where it would

seem more than probable that a fuller growth may be found.

The characters clearly differentiate this species from C. carolinianus

as fotmd on Perez Island; in many of its characters it is much nearer

C. echinatus as found abundantly on cultivated lands near Izamal,

eighty miles inland on the main, and on the rocky plain south of Pro-

greso. I am strongly inclined to judge the latter species to be its parent-

age. The fruiting characters of the two species are here illustrated

in conjunction. The species differ in the size of inflorescence; number

and size of the involucres; character of the basal bristles (barbellate in

*Reported as C. tribuloides L. in Field Mus. Bot. 2 144.

tThe specimen from Cozumel reported as this species under the description of

the type proves to be C. caroUnianus Walt.

April, 1916. Alacran Reef — Millspaugh 431

C. echinatus, glabrous in C. insiilaris); and in the shape and size as

well as the nervation of the first glume.

The plant is dispersionally avevectent, the burs attaching themselves

by their sharp, barbed bristles to the webbed feet of swimming birds

during their walks along the strand.

15. Philoxerus vermicularis (L.) R. Br.*

This species, common on the shores of the lagoon at Progreso and

Silam on the Yucatan mainland, is found on the Alacrans only on a

bare spot in the Sesuvium colony of Perez and Allison Islands.

From its position on the islands I am strongly inclined to judge its

dispersional character to be avevectent through the agency of small

migratory birds.

16. Boerhaavia repens Linn. Sp. PI. 3.!

This species was found only on one of the bare spots in the Sesuvium

carpet of Perez Island, where it nearly covered the small area in which it

had become implanted. It occurs also on the borders of the lagoon at

Progreso on the main but has not been gathered at any other part of

the Yucatan region.

In regard to the Alacran Reef the dispersional character of this

species is avevectent, the viscous-glandular fruits attach themselves to

the feet and feathers of migratory birds.

17. Opuntia Tuna (L.) Mill. Diet. ed. VIII :3.

Two low, spreading cltimps of this cactus were observed growing from

the interstices in the cairn of old coral heads thrown up in the center of

the north half of Perez Island. The plants were vigorous and had

apparently well adapted themselves to their environment.

Their location plainly indicates that, in this instance, the dispersional

character continues to be avevectent. That some migratory bird,

resting from flight upon the cairn, deposited the seed between the

topmost coral heads is evident.

18. Scaevola Lobelia Murr. Linn. Syst. ed. XIII :i 78.

One individual only of this seaside species was seen upon the islets

of the reef. This was growing directly under the left arm of the little

wooden cross erected at the head of the grave on the north end of Perez

Island. I removed a portion of this plant for herbarium purposes:

this may possibly affect its continuance.

The position in which the plant grew leaves no doubt as to the

avevectent character of its dispersion.

*Lithophila vermiculata Uline in Field. Mus. Bot. 2:39.

tDr. Heimerl considers our Alacran plant to be nothing but a form transitional

between the B. viscosum and B. hirsuta of Lagasca.