540 EUPHOilBIACEAE (^SPUKGE FAMILY) 



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

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

 less ; caruncle nearly as long as the seed. — Margins of 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 pedunded; vnngs lanceolate-ovate, pointless 

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



.^ ^_ Spikes slender (about 4 mm. thick), the bracts falling with the flowers, 

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

 keel larger. 



11. 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. amblgua (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. lutea L. Low; flovjers bright orange-yellow, in solitary ovoid or sub- 

 tylindric 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-yelloio, 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, fioi'ce 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 ^-celled, loith 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 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 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 (2-3-chotomous) ; stamens 10, erect in the bud. 



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



** ■>+ 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 glomerate. Ovary and fruit 3 (rarely 2-4) -celled. 

 3 Crotonopsis. Flo-^vars scattered on the branchlets. Ovary and fruit l-celled. 



