540 EUPHOKBIACEAE (SPL'RGE FAMILY) 



what spatulate or oblanceolate ; spikes sessile or nearhj so; wings broadly 

 ileltoid-ovate, sUghtbj heart-shaped, tapering to a hristhj point cr rarely point- 

 less ; caruncle nearly as long as the seed. — Margins of swamps, and occasionally 

 in drier places, s. Ale. to S. C, mostly near the coast ; and from Mich, to Minn, 

 and Neb. 



10. P. brevi'folia Nutt. Kather slender, branched above ; leaves scattered 

 on the branches, narrower ; spikes peduncled ; wings lanceolate-ovate, pointless 

 or barely mucronate. — Margins of sandy bogs, R. I., N. J., and southw. 



^ H_ Sjnkes slender (about 4 mm. thick), the bracts falling with the Jloicers, 

 which are small, greenish-white or barely tinged with purple, the crest of the 

 keel larger. 



11. P. verticillata L. Slender, 8-2."> cm. high, much branched ; stem-leaves 

 all whorled, those of the mostly opposite branches scattered, linear, acute ; 

 spikes peduncled, usually short and dense, acute ; wings round, clawed ; the 

 2-lobed caruncle half the length of the seed. — Dry soil, N. E., westw. and 

 southw. 



Var. ambigua (Xutt.) Wood. Usually taller (2-3.5 dm. high) ; leaves (and 

 branches) all scattered or the lowest in fours; spikes long-peduncled, more 

 slender, the flowers often purplish and scattered. (P. ambigua Nutt.) — Me. to 

 Mich., and southw. 



* * * * Biennials or annuals, with alternate leaves, cuid yellow flowers, which 

 are disposed to turn greenish in drying ; crest small ; flowering all summer. 



12. P. lutea L. Low; flowers bright orange-yellow, in solitary ovoid or snb- 

 cylindric heads (1.8 cm. thick) terminating the stem or simple branches ; leaves 

 2-5 cm. long» obovate or spatulate ; lobes of the caruncle nearly as long as the 

 seed. — Sandy swamps, L. I. to s. e. Pa., and southw. near the coast. 



13. P. ramosa Eil. Flowers lemon-yellow, in numerous short and dense 

 spike-like racemes collected in a flat-topped compound cyme; leaves oblong- 

 linear, the lowe.st spatulate or obovate ; seeds ovoid, minutely hairy, twice the 

 length of the caruncle. — Damp pine barrens, Del., and southw. June-Sept. 



14. P. cymbsa Walt. Stem short, naked above, the numerous racemes in a 

 u.sually almost simple cyme ; leaves narrow, acuminate ; seeds globose, icithout 

 caruncle. — Del., and southw. ; fl. midsummer. 



EUPHORBIACEAE (Spurge Family) 



Plants usually with a milky acrid juice, and monoecious or dioecious flowers, 

 mostly apetalous, somHimes achlamydeous (occasionally polypetalous or gamo- 

 pftalous) ; the ovary free and usually '^-celled, with one or sometimes two ovules 

 hanging from the summit of each cell ; stigmas or branches of the style as many 

 or twice as many as the cells ; fruit commonly a S-lobed capside, the lobes or 

 carpels separating elastically from a persistent axis and elastically 2-valved ; 

 seed anatropous; embi'yo straight, almost as long as and the flat cotyledons 

 mostly as wide as the fleshy or oily albumen. Stipules often present. — A vast 

 family in the warmer parts of the world ; most numerously represented in 

 northern countries by the genus Euphorbia, which has very reduced flowers 

 within a calyx-like involucre. 



* Flowers with a calyx, without involucre. 

 +- Seeds and ovules 1 in each cell. 

 ++ Flowers apetalous, in cymose panicles (2-8-chotomous) ; stamens 10, erect in the bud. 



1. Jatropha. Calyx corolla-like, the staminate salver-form. Armed with stinging hairs. 



*+ -M- Flowers in terminal racemes or spikes ; stamens inflexed in the bud ; stollate-downy or scurfy 



or hairy and glandular ; leaves mostly entire. 



2. Croton. Flowers spiked or glfunerate. Ovary and fruit .3 (rarely 2-4) -celled. 

 ■^. CrotonOQSis. Flowers scattered on the branchlets. Ovarv and fruit 1 -celled. 



