540 EUPHOEBIACBAE (SPURGE FAMILY) 



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

 deltoid-ovate, slightly heart-shaped, tapering to a bristly point or rarely point- 

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

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

 and Neb. 



10. P. brevif51ia Nutt. Rather 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. 



•>- -1- Spikes slender (about i mm. thick), the bracts falling with the flowers, 

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

 keel larger. 

 \/\\. P. verticillata L. Slender, 8-25 cm. high, much branched; stem-leaves 

 all whorled, tliose 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 (Nutt.) 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, and yellow flowers, which 

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



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

 cylindrie 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. rambsa Ell. Flowers lemon-yellow, in numerous short and dense 

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

 linear, the lowest 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 

 usually almost simple cyme ; leaves narrow, acuminate ; seeds globose, without 

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



EUPHORBlACEAE (Spurge Family) 



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

 mostly apetalous, sometimes achlamydeous {occasionally polypetalous or gamo- 

 petalous) ; the ovary free and usually 3-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 Z-lobed capsule, the lobes or 

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

 seed anatropous; embryo 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 woild ; most numerously represented in 

 northern countries by the genus Euphorbia, which has very reduced flowei-s 

 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-chotomou8) ; stamens 10, erect in the bud. 



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



++ ++ Flowers in terminal racemes or spikes ; stamens inflexed in the bud ; stellate-downy or scurfy, 

 or hairy and glandular ; leaves mostly entire. 



2. Croton. Flowers spiked or g;lomerate. Ovary and i^-uit 3(rarely 2-4)-cened. 

 8. Crotonoi^SiS. Flowers scattered on the branchlets. Ovary and iVuit 1-celled. 



