Order 112.— EUPHORBIAOE^. 625 



but loses Its (iGleteriouspropertieg by washing and expoauro to heat. Castor-oil Is expressed 

 from tho seeds of liicinus commuuls. Croton-oil from tlie eeeds of Oroton Tiglium. Caoutchouc 

 is yielded iu abaiidanee by seveml 8. Amoricau species. 



FIG. 687.— 1. Head or capUulum of Eu- 

 phorbia corol lata; with tho torolla-like in- 

 volucre, and pedicellate pistillate flower. 

 i2. The involucre tube cut open, showing 

 |/ the inonandroua, staniinate flowers sur- 

 yl rounding the pistillate. 8. One of tho 

 ■ ' £ flowers, with a toothed bract at base. 4. 

 Cross section of the ovary, showing the 3 

 one-seeded cells or carpels. 

 Obs. Our specimens of the Euphorblacere wore submitted to the inspection of Dr. Engelinanrie 

 of St. Louis, and are hero described nearly in accordance with his nomenclature. 



GENERA. 

 § Cells of the ovary onc-ovuled ; fruit 8 (rarely 2 or l)-seeded. {*) 



* Flowera in a cup-shaped involucre, the S many, each merely a stamen, with one 



? flower, an ovary exserted on a pedicel Euphorbia. 1 



* Flowers not in an involucre s, all apetalous, having a calyx only, (a) 



a Flowers diandrous, in a terminal spike. Plants glabrous Stillingia. 3 



a Flower 2 to 8-androus, in racemes. Plants hairy or downy Tkagia. 3 



a Flowers 8 to 12-androus, iu small spikes with large bracts Acalypii a . 4 



a Flowers 10 to 15-androus, in cymes, with white sepals. Stinging CxindscoLus. 5 



a Flowers polyandrous, in panicles ; fruit echinatc. Plant glabrous Ilioinus. 6 



* Flowers not iu an involucre s , tho sterile and often the fertile, also with i)etals. (b) 



b Ova. 3 (rarely 2)-celled and seeded, Fls. clustered. "Woolly, downy or scurfy.CiiOTo:?. 7 

 ta Ova, 1-celled, 1-seedcd, indehiscent. Fls. axillary, small. Silvery scurfy. Cboton ops ib, S 

 § Cells of the ovary 2-ovuled ; fruit 6 (or abortively fewer) -seeded, (c) 



G Calyx 6-parted ; stamens 8, iinited. Flowers axillary, small Putllantiius. 9 



C Calyx i-parted ; stamens 4, distinct, large. Flowers in bracted spikes Paciiysaxdka. 10 



Calyx 4-parted ; stamens 4, distinct Flowers axillary. Shrub. Leaves opposite. , BuxuB. It 



1. EUPHOR'BIA, L. (Named for IJupkorhus, physician to Juba, 

 King of Mauritania.) Spurge, Flowers 8 , several in an involucratc 

 cluster ; involucre calyx;-like, cup-shaped, with 4 or 5 petaloid segments 

 alternate with as many large glands ; f owers achlamydeous, the ^ 12 

 or more each consisting of a single stamen on a pedicel which is axil- 

 lary to a little bract ; $ flower solitary, central, a 3-carpeled, 3-stylcd 

 and 3-seeded ovary raised on a slender pedicel ; capsule 3-lobcd, separ- 

 ating into 3 bivalved nutlets. — Herbs or shrubs with a milky juice. 

 Lvs. generally opposite or verticillate, often alternate, sometimes none. 

 Involucres flower-like, axillary or umbellate. 



g stems spiny, thick, erect.— Stipules none. Floral leaves scarlet No. 1 



^ Stems unarmed, erect. Leaves destitute of stipules, alternate or opposite. (*) 



* involncro with 4 or 5 glands which are 2-horned or crescent-shaped, (a) 



a Umbel of many rays. Stem-leaves narrow, alternate. Seeds smooth, if Nos. 2, 3 



a Umbel of 8 rays, and forked. — Stem leaves alternate, thin Nos. 4, 5 



a Umbel of 8 or 4 rays, and forked.— Stem leaves opposite, thick No. 6 



* Involucre with 5 white, petal-like glands or appendages, (b) 



b Heads nearly sessile. Leaves with broad, white margins No. 7 



b Heads pedunculate, solitary or snbpanieulate. Leaves broad oval Nos. 8, 



b Heads pedunculate, umbellate. Leaves oblong, mostly n.irrow. Nos. 10, 11 



* Involucre with 1 to 5 glands neither petal-like nor horned, (c) 



C Inflorescence iu compound cymes, with long peduncles No*. 12 



C Inflorescence in compouud umbels, with short peduncles, (d) 



d Seeds reticulated or wrinkled. Leaves serrulate Nos. 13, 14 



d Seeds smooth and even, in a rough', warty fruit Nos. 15, IG 



C Inflorescence solitary, axillary. Leaves all opposite : No. 17 



C Inflorescence a simple, terminal cluster. Leaves alternate or opposite Nos. IS, 19 



§ Stems unarmed, chiefly prostrate, diffuse. Leaves all opposite, small, with small, 



entire or cleft stipules. Involucres axillary or clustered. May to Nov. (T) (e) 

 e Leaves serrulate or serrate. Seeds roughened with wrinkles or pits, (f ) 



f Stem ascending or erect, smooth or smoothish. Seeds black or amber color. Nos. 20, 21 



f Stem prostrate, hairy or puberulent as well as the leaves and fruit Nos. 22, 23, 24 



e Leaves entire. Seeds jsmooth and even. Plants glabrous Nos. 25, 26, 27 



1 E. splendens Eojaris. St. suffruticous, fleshy, armed witb rigid, sharp 

 thorns ; lvs. ovate, tapering to the base, glabrous, entire, acute, mucronate ; ped, 

 aziUary, 2 or 3 times dichotomous ;• floral lvs. in pairs, broader than long, cuspi- 

 date, scarlet. — A singular and showy garden plant, f Madagascar. 



40 



