April 30, 1913 35 
SPOROBOLUS CRYPTANDRUS (Torr.) Gray 
Rare along Hat creek; also in Washington county. Men- 
tioned by Saunders only from east of the Missouri, though Ryd- 
berg collected it in the Hills. 
CYPERUS SCHWEINITzII Torr. 
Local'y common on Softwater creek, also in Harding and 
Washabaugh counties; (eastern South Dakota). 
Scirpus campestris Britton 
Abundant along alkali streams. 
Scirpus microcarpus Presl 
Everywhere along streams. 
CAREX AUREA Nutt. 
Rare along streams. Also in Harding county; (near Lead). 
CAREX NEBRASCENSIS Dewey 
Very plentiful along streams; (near Lead). 
JUNCUS LONGISTYLIS Torr. 
Plentiful along permanent streams; also in Bennett county; 
(near Lead). 
POPULUS OCCIDENTALIS (Rydb.) Britton. Western cottonwood. 
Dominant on the larger streams. This was formerly in- 
cluded in P. deltotdes. Rydberg states that the name occzden- 
talis is preoccupied by fossil forms, and hence this species should 
be called P. Sargentz. 
Salix amygdaloides Anders.? Peach leaved willow. 
Abundant in valleys. 
SALIX EXIGUA Nutt. 
Forming thickets on flood plains of all running streams; 
(also in Bennett county). Included by Rydberg in 1894 in |S. 
fluviatilis. 
POLYGONUM HARTWRIGHTII Gray? Simartweed. 
Common along streams; (Sioux valley). 
Polygonum tncarnatum Fl, 
Frequent along streams. 
