April 30, 1913 37 
PSORALEA LANCEOLATA Pursh 
Especially numerous along terraces; (southern Sioux val- 
ley). 
Thermopsts montana Nutt. 
Infrequent on the plains. 
Euphorbia cuphosperma (Engelim.) Boiss. Spurge. 
Rate; Indian creek valley. Included by Rydberg in 1896 
as £. dentata. 
Rhus Rydbergi Small. Western poison ivy. - 
Common about rocks and along valleys; collected also in 
Shannon and Harding counties. Included in 1896 as R. radz- 
cans toxicodendron. 
Parthenocissus vitacea A. §. Hitche. Virginia creeper. 
In woods along moist valleys, frequent; also in Washabaugh 
county. 
Opuntia polyacantha Haw. Prickly pear. 
Common on the foothills; also in Harding county. 
EPILOBIUM HORNEMANNI Reichenb. 
General along all living streams; (“‘near Sip’s Spring in the 
Black Hills.’’) 
Onagra strigosa Rydb. Evening primrose. 
Tolerably frequent along flood plains. 
ASCLEPIAS SPECIOSA Torr. Showy milkweed. 
Abundant in the larger valleys, also in Washabaugh county; 
(in the Minnesota and Sioux valleys). 
Cuscuta plattensts A. Nelson? Dodder. 
Locally abundant on flood plains. 
GILIA CONGESTA Hook. 
Abundant on the foothills. Rydberg has withdrawn his 
G. cephaloides. The Black Hills Gilias mentioned by Saunders 
under G. specata capitata belong here. 
Phacelia leucophyila Yorr. 
Infrequent on hillsides. 
