1 83 

 Apocynace^. — Dogbane Family. 



Apocyiiuin androsji^miioliuiii, L. Spreading Dogbane. 

 In thickets in the Minnesota and Sioux valleys and in 

 the Black Hills. 



Apocynuiii caiiiiabiimiu, L. Indian Hemp. 



On dry banks from the Missouri valley eastward. 



AsCLEPiADACE^. — Milkweed Family. 



Asclepias tiiberosa, h. Pleurisy Root. Butterfly Weed. 

 In thickets in the southern part of the Sioux valley; 

 Union county. 



Asclepias incariiata, L. Swamp Milkweed. 



In swamps from the Missouri valley eastward. 



Asclepias syriaca, L. Common Milkweed. 

 Asclepias Cornuti^ Dec. 



On prairies and in thickets in the Minnesota and 

 Sioux valleys. 



Asclepias speciosa, Torr. Showy Milkweed. 



In low ground in the Minnesota and Sioux valleys. 



Asclepias ovalifolia, Dec. Oval-leaved Milkweed. 



On prairies in the Minnesota and Sioux valleys, and 

 in the Black Hills; rare. 



Asclepias verticillata, L. Whorled Milkweed. 



Common on banks and prairies from the Missouri val- 

 ley eastward. 



Asclepias puniila, (Gray.) Vail. Low Milkweed. 

 Asclepias verticillata pumila^ Gray. 



Common on the dry plains from the Missouri valley 

 westward, seems to replace the last. 



Acerates viricliflora, (Raf.) Eaton. Green Milkweed. 

 Occasional in sandy soils throughout the state. 



Acerates aiigustifolia, (Nutt.) Dec. Narrow-leaved 

 Milkweed. 



In the Black Hills and the adjacent plains. 



