94 Order GERANIALES 
Seeds strongly transversely wrinkled. 7. E. glyptosperma. 
Plants erect or ascending; leaves 10 to 30 mm. long. 
11. E. preslii. 
Plants more or less hairy. 
Seeds narrow, twice as long as wide. 6. E. stictospora. 
Seeds not twice as long as wide, faces wrinkled. 
Involucre not split; leaves mostly blotched. 8. E. maculata. 
Involucre deeply split on one side. 9. E. humistrata. 
Leaves equilateral at the base, not oblique; plants erect. 
Leaves opposite, or alternate, not verticillate, petioled. 
Leaves all opposite, entire; glands of involucre five, each with a 
petaloid appendage; stem striate-angled. 12. E. hexagona. 
Leaves some of them alternate, involucre with 1 to 4 glands, ap- 
pendages usually wanting. 
Leaves linear to linear-lanceolate. 15. E. cuphosperma. 
Leaves broader. 
Leaves mostly opposite, coarsely dentate, uniform. 
16. E. dentata. 
Leaves mostly alternate, variable in shape, gland sessile. 
17. E. heterophylla. 
Leaves at base of inflorescence verticillate, the lower alternate or 
scattered, sessile. 
Leaves entire. 
Upper leaves white-margined. 14. E. marginata. 
Upper leaves not white-margined. 
Leaves 2 to 4 cm. long; glands of the involucre with peta- 
loid appendages. 13. E. corollata. 
Leaves smaller, the lower often reduced to scales. 
Rays of the umbel few, with few leaves in the whorl at 
its base. 21. E. robusta. 
Rays of the umbel numerous, with numerous leaves in 
the whorl at its base. 20. E. cyparissias. 
Leaves serrulate; capsule warty. 
Seeds dark brown, faintly reticulated. 18. E. obtusata. 
Seeds reddish brown, distinctly reticulated. 19. E. missouriensis. 
1. Euphorbia petaloidea Engelm. 
Common in the western part of the state, in sandy soil. Anselmo; 
Banner county; Benkelman; Brunswick; Franklin; Pine Ridge; 
Schuyler; Sheridan; Sioux county; Valentine; Weigand. 
2. Euphorbia flagelliformis Engelm. 
Ft. Robinson; Valentine. 
3. Euphorbia geyeri Engelm. & Gray. 
On dry, sandy ridges and bluffs in the western part of the state. 
Long Pine; Natick; Paddock; Plummer Ford; Thedford; Valentine. 
4. Euphorbia serpens H. B. K. 
In prairies all over the state. Bassett; Kennedy; Lincoln; Niobrara; 
Red Cloud. 
5. Euphorbia serpyllifolia Pers. 
In prairies and meadows throughout the state. Grand Island; Lin- 
coln; Niobrara; Saunders county; Valentine. 
6. Euphorbia stictospora Engelm. 
Nebraska, according to Britton and Brown. 
