ASCLEPIADACEAE. 271 



Leaves narrowly linear, verticillate or scattered. 



Plant tall, 4-6 dm. high from a rootstock ; leaves verticillate. 



Hoods entire. 9. A. verticillata. 



Hoods dorsally hastate-sagittate. 10. A. galioides. 



Plant low, 1-2 dm. high, bushy from a ligneous base ; leaves scattered. 



II. A. pumila. 



1. Asclepias speciosa Torn On river bottoms and in fields from Man. and 

 B. C. to N. M. and Calif. — Alt. 40DO-8000 ft. — Ft. Collins; Mancos; Denver; 

 Wahatoya Caiion ; Piedra ; Colorado Springs; Grand Junction; Boulder. 



2. Asclepias cryptoceras S. Wats. In dry soil from Ida. and Ore. to Colo. 

 — Grand Junction. 



3. Asclepias latifolia (Torr.) Raf. {A. obtusifolia latifolia Torr. ; A. 

 Jamesii Torr.) On plains from Colo, to Tex. and Ariz. — Hotchkiss; Caiion 

 City. 



4. Asclepias arenaria Torr. In sandy soil from Neb. and Colo, to Okl. 

 and N. ]\I. — Locality not given. 



5. Asclepias Hallii A. Gray. In gravelly soil in Colo. — Alt. 7000-9000 ft. — 

 Calhan ; Veta Pass ; Gunnison ; La Veta ; Buena Vista ; Arkansas River. 



6. Asclepias brachystephana Engelm. In sandy soil from Wyo. to Tex. 

 and Ariz. — " On the plains." 



7. Asclepias uncialis Greene. In sandy soil from Wyo. to N. M. and 

 Ariz.— " Colorado " {Hall & Harbour). 



8. Asclepias incarnata L. In swamps and wet meadows from N. B. and 

 Man. to Fla. and N. M. — Alt. 4000-6000 ft. — Ft. Collins; Timnath, Larimer 

 Co.; Denver; Cache la Poudre; Boulder. 



9. Asclepias verticillata L. In dry fields and on hills from Me. and N. D. 

 to Fla. and Ariz. — Rocky Ford; Paonia; Colorado Springs. 



10. Asclepias galioides H. B. K. In dry soil from Kans. and Colo, to 

 Ark. and Ariz. ; also Mex. — Exact locality not given. 



11. Asclepias pumila (A. Gray) Vail. {A. verticillata pumila A. Gray) 

 Dry plains and in sandy soil from S. D. and Mont, to Ark. and N. M. — 

 Alt. 4000-7000 ft. — Near Ft. Collins; East Park, Denver; headwaters of 

 Clear Creek; Boulder; Colorado Springs; along Platte River, Denver; 

 Ft. Collins ; Manitou ; gulch, Soldier Cafion ; Boulder. 



3. ASCLEPIODORA A. Gray. 



I. Asclepiodora decumbens (Nutt.) A. Gray. In dry sandy soil from Kans. 

 and Nev. to Ark., Tex. and Ariz. ; also Mex. — Alt. 7000-8000 ft.— Near 

 Badito, between La Veta and Gardner; Arboles; Hortense Springs; Durango; 

 Walsenburg; Dolores. 



Order 44. POLEMONIALES. 



Stamens s, if only 4, not didynamous. 



Fruit a capsule or berry ; ovary not 4-lobed. 

 Styles or stigmas usually distinct. 



Parasitic twining plants with scale-like leaves. iii. Cuscutaceae. 



Plants not parasitic ; leaves normal. 



Inflorescence not scorpoid ; flowers cymose or solitary ; ovary 2-3-celled ; 

 micropyle of the seed turned downward. 



