548 EUPHOKBIACEAE (SPURGE FAMILY) 



AA. Glands of the involucre without petaloid appendages. 



§ 5. POINSETTIA (Graham) Baill. Involucres in terminal clusters^ i-b-lobed. 

 with few (or often solitary) cup-shaped glands; erect annuals, icith entire, 

 dentate, or sinuate leaves, all or only the iipper ones opposite^ the iippermost 

 often colored, especially at base ; stipules reduced to small glands. 



17. E. dentata Michx. Erect or ascending, hairy, 2.5-12 dm. high; leaves 

 ovate, lanceolate, or linear, petioled, coarsely toothed, 4-8 cm. long, only the 

 lowest alternate, the upper often paler at base ; involucres almost sessile, with 

 5 oblong dentate lobes, and one or sometimes more short-stalked glands ; seeds 

 ovoid-globular, slightly tubercled. — Rich soil, Pa. to Wyo, and Tex. July-Sept. 



18. E. heterophylla L. (Painted Leaf.) Erect. 3-0 dm. high, glabrous ; 

 leaves alternate, petioled, ovate-fiddle-shaped and sinuate-toothed, or lanceolate 

 or linear and entire, often only those of the branches linear ; the upper usually 

 ^\ith a red base ; involucres about the length of the peduncle, with -5 ovate incised 

 lobes and one or few almost sessile glands; seeds nearly globular, tubercled. — 

 Slopes and rocky soil, Minn, to w. 111., Kan., Tex., and Fla. 



§ 6. TITHYMALUS [Tourn.] Pers. Involucres in a terminal dichotomous or 

 commonly umbelliform inflorescence, 5- or usually ^-lobed, xoith as many 

 flat or convex entire or crescent-shaped glands; seeds carunculate {except 

 in no. 19) ; ours ascending or erect, and mostly glabrous, without stipules. 



* Perennials icith entire leaves, all or only the upper opposite ; involucres long- 



peduncled in a dichotomous inflorescence, mostly with 5 transversely oblong 

 glands; seeds without caruncle. 



19. E. Ipecacuanhae L. Stems many from a very long perpendicular root, 

 erect or diffusely spreading, 1-2.5 dm. long, forking from near the base ; 

 leaves varying from obovate or oblong to narrowly linear, almost sessile, 

 glabrous; peduncles elongated (1. .3-2.5 cm. long) ; pod long-pediceled, obtusely 

 angled, nearly smooth ; seed ovoid, white, sparsely marked with impressed dots. 

 — Sandy soil, near the coast, Ct. to Fla. ; also barrens of s. Ind. 



* * Leaves scattered, only the floral in the umbelliform inflorescence whorled or 



opposite and of a different shape ; glands mostly 4. 



•»- Leaves serrulate or rarely entire; glands transversely oval, obtuse. 

 ++ Seeds smooth and even ; pod warty or rough. 



20. E. Darlingtbnii Gray. Tall perennial, 6-12 dm. high ; leaves entire, 

 minutely downy beneath; those of the stem lanceolate-oblong from a narrow 

 base ; the floral oval, very obtuse ; the upper roundish-dilated with a truncate 

 base ; umbel 5-8-rayed, then simply forked ; pod minutely warty ; large globular 

 seed with a small caruncle. — Cop.ses, Pa. to the mts. of N. C. July-Sept. 



21. E. obtusata Pursh. ^rect annual, ^-Q dm. higla.; leaves oblong-spatidate, 

 minutely serrulate, smooth, all obtuse ; upper ones cordate at base ; floral (mes 

 ovate, dilated, barelj'- mucronate ; umbel once or twice divided into 3 rays, then 

 into 2 ; involucre with naked lobes and small stipitate glands ; styles distinct, 

 longer than the ovary, erect, 2-cleft to the middle ; pod beset with long warts. — 

 Damp woods. Pa. to S. C, w. to la , Kan., and (?) Tex. 



22. E. PLATYPHYLLA L. Ercct annual. 2-4.5 dm. high ; upper stem-leaves 

 lanceolate-oblong , acute, cordate at base, minutely serrulate, mostly with scat- 

 tered hairs beneath ; floral ones triangular-ovate, subcordate ; umbel 5-rayed ; 

 involucre with ciliate lobes and large sessile glands ; styles longer than the 

 ovary, united at base, slightly '2-cleft; pod covered with depressed warts. — 

 L. Champlain to w. Pa. and Man. June- Aug. (Nat. from Eu.) 



t-t- ++ Seeds rugose or reticulated ; leaves serrulate; annuals. 



23. E. dictyosperma Fi.sch. & Mey. Stem erect, 2-4.5 dm. high ; leaves 

 oblong- or obovate-spatulate, smooth, all obtuse and obtusely serrate; upper 

 ones cordate at base ; floral ones roundish-ovate or obscurely heart-shaped, 

 slightly uuicronate ; umbels once or twice 3-forked, then 2-forked ; involucre 



