EUPHORBIACE.E. (SPURGE FAMILY.) 327 



2. Leaves opposite, on short petioles, equal at base, with stipular glands : stems 

 dichotomously branched, erect : cymes terminal, involucres with 5 glands : seeds 

 tuberculate. 



10. E. hexagona, Nutt. Somewhat hairy: stem a foot or more high; 

 branches striate-angled : leaves linear-lanceolate, entire : involucre hairy with- 

 out and within : glands with a green ovate-triangular appendage twice their 

 length: capsule smooth: seeds ovate. From Texas and Colorado to the 

 Upper Missouri. 



3. Uppermost or floral leaves with conspicuous white petal-like margins, whorled 

 or opposite, the others scattered, equal at base, entire and sessile : involucres 

 5-lobed, collected in an umbel-like inflorescence. 



11. E. marginata, Pursh. Stem stout (2 to 3 feet high), erect, hairy : 

 leaves ovate or oblong : umbel with 3 dichotomous rays : glands of the 

 involucre with broad white appendages. From Colorado to Kansas and 

 Nebraska. Cultivated and run wild in the Eastern States. 



B. Glands of the involucre without petaloid appendages. 



4. Involucres in terminal clusters, 4 to 5-lobed, with few cup-shaped glands : 

 seed without a caruncle: leaves dentate, all but the lowest opposite, and 

 stipules glandular. 



12. E. dentata, Michx. Erect or ascending, hairy : leaves ovate, lanceo- 

 late, or linear, petioled, coarsely toothed, upper ones often paler at the base : 

 involucres almost sessile, with 5 oblong dentate lobes, and one or more short- 

 stalked glands : seeds ovate-globular, slightly tubercled. S. Colorado ( Bran' 

 degee) and eastward to Illinois and Pennsylvania. 



5. Involucres in a terminal dichotomous or commonly umbelliferous inflorescence, 

 4 or 5-lobed, with as man]) flat or convex entire or crescent-shaped glands : seeds 

 mostly carunculate : glabrous, with entire or serrulate scattered (except the 

 uppermost) leaves and no stipules. 



13. E. Obtusata, Pursh. Erect: leaves oblong-spatulate, minutely serru- 

 late, smooth, obtuse ; upper ones cordate at base ; floral ones ovate, dilated : 

 umbel once or twice divided into 3 rays, then into 2 : involucre with naked 

 lobes and small stipitate glands : styles distinct and longer than the ovary, erect, 

 2-clef t to the middle : pod beset with long warts : seeds smooth and even. 

 S. Colorado, and from Illinois to Virginia. 



14. E. dictyosperma, Fisch. & Meyer. Erect : leaves oblong- or ovate- 

 spatulate, smooth, obtuse and obtusely serrate ; upper ones cordate at base : 

 umbels once or twice 3-forked, then 2-forked : involucre with nearly naked 

 lobes and small almost sessile glands : styles shorter than the ovary, spreading or 

 recurved : pod warty : seeds delicately reticulated. From California and Ore- 

 gon to Texas, Kentucky, and Nebraska. 



15. E. montana, Engelm. Very glabrous and glaucous: stems leafy 

 and ascending : leaves rather thick, entire, ovate, obtuse ; floral ones orbiculate, 

 triangular: umbels repeatedly dichotomous: involucre roughish within, with 

 oblong-linear velvety lobes, and truncate, very shortly 2-horned glands : styles 

 very short, bifid : pod smooth : seeds superficially pitted. From the Upper 

 Platte to New Mexico, Arizona, and southward. 



