Herbs, shrubs or trees, usually with a milky, acrid juice. Flowers diclinous, some-times enclosed in a cup-shaped involucre. Calyx inferior, sometimes wanting. Cor-olla scale-like or colored, often wanting. Ovary free, sessile or stipitate, 2, 3 (or more)-carpeled; styles distinct or united. Fruit of 2, 3 (or more), 1 to 2-seeded carpels (rarely of 1 carpel) united to a common axis, at length separating. Embryo in fleshy albumen. Fig. 371.
Genera 200, species 2500 (Lindley). chiefly natives of S. America, not more than 60 specie. being found in N. America, north of Mexico.
Properties. - An acrid, stimulant and poisonous principle, residing chiefly in the milky juice, pervades the whole order. This principle varies in activity from mild stimulant'* to the most active poisons; hut it is volatile and easily expelled by heat. Tapioca is a starch-like accumulation formed in the roots of the Jatropha Maniliol When fresh this root is a violent poison.
but loses its deleterious properties by washing and exposure to haat. Castor-oil is expressed from the seeds of Ricinus communis. Croton-oil from the seeds of Croton Tiglium. Caoutchouc is yielded in abundance by several S. American species.
FIG. 687. - 1. Henri or capitulum of Eu-phorbiacorollata; with the corolla-like involucre, and pedicellate pistillate flower. 2. The involucre tube cut open, showing the monandrous, staminate flowers surrounding the pistillate. 3. One of the & flowers, with a toothed bract at base. 4. Cross section of the ovary, showing the 3one-seeded cells or carpels.
Obs. Our specimens of the Euphorbiaceae were submitted to the inspection of Dr. Engclmans, of St. Louis, and are here described nearly in accordance with his nomenclature.
§ Cells of the ovary one-ovuled; fruit 3 (rarely 2 or l)-seeded. (*)
* Flowers in a cup-shaped involucre, the many, each merely a stamen, with one
flower, an ovary exserted on a pedicel.................................
* Flowers not in an involucre 8, all apetalous, having a calyx only, (at
a Flowers diandrous, in a terminal spike. Plants glabrous............
a Flower 2 to 3-androus, in racemes. Plants hairy or downy........
a Flowers 8 to 12-androus, in small spikes with large bracts...........
a Flowers 10 to 15-androus, in cymes, with white sepals Stinging......
a Flowers polyandrous, in panicles', fruit echinate. Plant glabrous.......
* Flowers not in an involucre 8, the sterile and often the fertile, also with petals, (b)
b Ova. 3 (rarely 2)-celled and seeded, Fls. clustered. Woolly, downy or scurfy.
b Ova, 1-celled, 1-seeded, indehiscent. Fls. axillary, small. Silvery scurfy.
§ Cells of the ovary 2-ovuled; fruit 6 (or abortively fewer)-sceded. (c)
c Calyx 6-parted; stamens 3, united. Flowers axillary, small.................
c Calyx 4-parted; stamens 4, distinct, large. Flowers in bracted spikes....
c Calyx 4-parted; stamens 4, distinct. Flowers axillary. Shrub. Leaves opposite....
1. EUPHOR'BIA, L. (Named for Euphorbus, physician to Juba, King of Mauritania.) Spurge. Flowers 8 , several in an involucrate cluster; involucre calyx-like, cup-shaped, with 4 or 5 pctaloid segments alternate with as many large glands; flowers achlamydcous, the 1 2 or more each consisting of a single stamen on a pedicel Which is axillary to a little bract; flower solitary, central, a 3-carpeled, 3-styled and 3-scedcd ovary raised on a slender pedicel; capsule 3-lobed, separating into 3 bivalved nutlets. - Herbs or shrubs with a milky juice. Lvs. generally opposite or vcrticillate, often alternate, sometimes none. Involucres flower-like, axillary or umbellate.
§ Stems spiny, thick, erect. - Stipules none. Floral leaves scarlet....................
§ 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. ............
Nos. 2, 3
a Umbel of 3 rays, and forked. - Stem leaves alternate, thin...........
a Umbel of 3 or 4 rays, and forked. - Stem leaves opposite, thick.,.......
* Involucre with 5 white, petal-like glands or appendages, (b)
b Heads nearly sessile, Leaves with broad, white margins........................
b Heads pedunculate, solitary or subpaniculate. Leaves broad oval...........
Nos. 8, 9
b Heads pedunculate, umbellate. Leaves oblong, mostly narrow........
* Involucre with 1 to 5 glands neither petal-like, nor horned, (c)
c Inflorescence in compound cymes, with long peduncles.........................
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............................
c Inflorescence a simple, terminal cluster. Leaves alternate or opposite
Nos. 18, 19
§ Stems unarmed, chiefly prostrate, diffuse. Leaves all opposite, small, with small entire or cleft stipules. Involucres axillary or clustered. May to Nov. (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 smooth and even. Plants glabrous...............................
Nos. 25, 26, 27
1 E. splendens Bojaris. St. suffruticous, fleshy, armed with rigid, sharp thorns; lvs. ovate, tapering to the base, glabrous, entire, acute, mucronate; ped. axillary, 2 or 3 times dichotomous; floral lvs. in pairs, broader than long, cuspidate scarlet. - A singular and showy garden plant. + Madagascar.
2 E. Cyparissias L. Cypress Spurge. Lvs. linear-setaceous, crowded on the stem, with a spiral arrangement; floral lvs. broadly cordate, all sessile; umbel of many simple rays, with several scattered branches below it; glands crescent-shaped; fr. granulated. - Gardens and fields, rare. Sts. much branched, ascending If high, with numerous leaves 6 to 10" long, less than 1" wide, the floral yellowish, very different. § Eur.
3 E. Esula L. Lvs. lanceolate-linear, the floral broadly cordate, mucronate, umbel of many rays, the rays forked, with scattered branches below it; glands 2-horned; fruit nearly smooth. - Fields, Mass. (Oakes), not common. Sts. much branched, If high. Lvs. 1' or more long, the floral yellowish. Glands brown. § Eur.
4 E. Peplus L. Lvs. membranous, roundish, tapering into the petiole, very obtuse, entire, smooth, the upper floral ovate; umbel of 3, rarely 5 rays, then forked; glands lunate, with 2 long horns; ovaries with a double-winged keel at the lack, rugous and scabrous; seed dull grayish white, with 2 longitudinal furrows and 4 rows of dots. - Waste places, N. Eng., rare. St. 7 to 12' high. § Eur.
5 E. commutata Engelm. Decumbent and branched at base, smooth; sts. erect; lower lvs. oval, peliolate; floral lvs. numerous, thin, broader than long, all sessile, very obtuse; ovaries obtusely angled, not winged, seeds dotted all over. - Along streams, W. Va. to Ohio, Ill. frequent, and S. to Fla. Sts. a foot high, once or twice trichotomous, the floral lvs. so applied at base as to appear orbicular and perfoliate, 6 to 9" diam. Horned glands usually but 4. - Has been confounded with E. Peplus. Jn.
6 E. Lathyris L. Mole-tree. Caper Spurge. St. erect, stout, smooth; lvs. lance-linear, rather acute, entire, glabrous, sessile; umbel mostly 4-rayed, rays dichotomous; glands of the invol lunate, 2-horned, the horns dilated and obtuse. - Cultivated grounds and gardens. Stem 2 - 3f high. Leaves 2 - 4'by 3 - 9', numerous and arranged in 4 rows on the stem. Umbel of 4 vcrtreillate branches with a central subsessile head. Jl - Sept. § Eur. - Supposed efficacious in expelling moles from the ground.
7 E. marginata Pursh. Lvs. oblong-lanceolate, subcordate, sessile, acute, mucronate, entire on the margin, glabrous; umbel 3-rayed, once or twice dichotomous; involucrate lvs. oblong, cordate, colored and membranaceous at the margin; inner segments of the floral involucre roundish; caps, hoary-pubescent. - A handsome species, remarkable for the variegated leaves of the involucre, † Shores of the Ky. River at Paris, abundant. Doubtless escaped from the gardens. § Native in Nebraska.