Order 112.— EUPHORBIACEjE. C25 



but lofo* its deleterious properties by washing and exposuro to heat. Castor-nil is oppressed 

 from tlie seeds of Iiicinus communis. Croton-oil from the seeds of (Jroton 'i'lglium. Caoutchouo 

 is yielded in abundance by several S. American species. 



FIG. 687.— 1. Head or capitulum of En 

 phorbiacorollata; with the corolla-like in- 

 volucre, ami pedicellate pistillate flower. 

 2. The involucre tube cut open, showing 



J tho monandrous, staminatc flowers sur- 

 ¥/ rounding tli 



„ the pis tlj late. 8. One of tho 

 »)(/ & flowers, with a toothed bract at base. 4. 

 Cross section of tho ovary, showing the 3 

 one-seeded cells or carpels. 

 0!'K. Our specimens of the Enphorbiacea? were submitted to the inspection of Dr. Engelmann, 

 «{ St. Louis, and arc here described nearly in accordance with his nomenclature. 



GENERA. 

 § Cells of tho ovary one-ovuled ; fruit 3 (rarely 2 or l)-soeded. (*) 



* Flowers in a cup-shaped involucre, the $ many, each merely a stamen, with ono 



$ flower, an ovary exsertod on a pedicel Euphorbia. 1 



* Flowers not in nninvolucro a, all apetalous, having a calyx only, (a) 



a Flowers diandrous, in a terminal spike. Plants glabrous Stillingia. 8 



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



a Flowers S to 12-audrous, in small spikes with largo bracts Acalvimia. 4 



a Flowers 10 to 15-androus, In cymes, with white sepals. Stinging CnidoscoluB. 5 



a Flowers polyandrous, in panicles ; fruit echinate. Plant glabrous Lioinus. t, 



* Flowers not in an involucre 8, tho sterilo and often the fertile, also with petals, (b) 



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

 b Ova. 1-celled, 1-secded, indehiseent. Fls. axillary, small. Silvery scurfy. Crotonopsis. 8 

 5 Cells of tho ovary 2-ovuled ; fruit C (or abortively fewer)-seeded. (c) 



C Calyx C-parted ; stamens 3, united. Flowers axillary, small Piiyllajttiius. 9 



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



C Calyx 4-parted ; stamens 4, distinct. Flowers axillary. Shrub. Leaves opposite.. Buxus. 11 



i. tUPHOR'BIA, L. (Named for Euphorbus, physician to Juba, 

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

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

 alternate with as many large glands ; flowers achlamydcous, 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-carpclcd, 3-styled 

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

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

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

 Involucres flower-like, axillary or umbellate. 



§ Stems spiny, thick, erect. — Stipules none. Florid loaves scarlet No. 1 



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



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



a Umbel of many rays. Stem-leaves narrow, alternate. Seeds smooth. 71. . . .".\o%. 2, 3 



a Umbel of 3 rays, and forked. — Stem leaves alternate, thin Nos._4, 5 



a Umbel el* 3 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 snbpaniculate. Leaves broad oval Nos. S, 9 



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



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



C Inflorescence in compound cymes, with long peduncles No. 12 



C Inflorescence in compound 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, 16 



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



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

 J 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 smoothUh. Seeds black or amber color. Nos. 20, 21 



f Stem prostrate, hairy or puberulent as well as the leaves and fruit Nos. 28, 23, 24 



o Leaves entire. Seeds smooth and even. Plants glabrous Nos. 25, 26, 27 



1 E. splendens Bojaris. St. suffrutieous, fleshy, armed with rigid, sharp 

 thorns; lvs. ovate, tapering to tho base, plabrous, entire, acute, mueronate; ped. 

 axillary, 2 or 3 times dichotorr.ous ; floral lvs. in pairs, broader than long, cuspi- 

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



40 



