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. 4000-8000 ft. Ft. Collins; Mancos; Denver; 

 Wahatoya Canon; 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; Canon 

 City. 



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

 and N. M. 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 6- 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 Canon; 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 5, 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. in. CUSCUTACEAE. 



Plants not parasitic ; leaves normal. 



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

 micropyle of the seed turned downward. 



