METCALF: NOTES ON NORTH DAKOTA PLANTS 1 93 



Co. (No. 507, Sept. 20, 1917, D. C. Mabbott), similar to Minto Lake 

 with a total concentration of salts of 25,210 parts per million. Un- 

 fortunately fruit in many cases could not be found but after this sum- 

 mer's investigation of numerous lakes of extremely different types, 

 evidence in North Dakota seems to point to the fact that the so-called 

 species and varieties of this plant are primarily connected with the 

 concentration of salts in the water. Bergman reports this plant only 

 from Dawson. 



Najas marina Linnaeus. Not previously reported from the state. 

 Range extended westward as manuals give Minnesota as the extreme 

 northwestern limit. Only observed in Lake Elsie (No. 60, July 23, 

 1917) and Mud Lake (No. 148, July 24, 1917), Richland Co., where it 

 was fairly abundant. 



Sagittaria latifolia Willdenow. Rare; only reported from Mud Lake 

 Richland Co. (No. 135, Aug. 24, 1917); Dawson Slough and Horseshoe, 

 Lake, Kidder Co. (No. 325, Aug. 18, 1917). Bergman reports this from 

 Neche. 



Elodea canadensis Michaux. Frequent throughout the state in fresh 

 water ponds and sloughs; observed in Bismarck Slough, Burleigh Co. 

 (No. 358, Aug. 24, 1917); John Wilde Lake, Emmons Co.; Mercer and 

 Max Lakes, McLean Co.; Ward Lake (No. 569, Oct. 2, 1917), Clayton 

 Twp., S. 30-29 Lake (No. 590, Oct. 5, 1917), and Foothills Twp., S. 28 

 Lake in Burke Co. and Jim Lake (No. 321a, Aug. 14, 1917, D. C. 

 Mabbott) in Stutsman Co. Bergman records this plant from La 

 Moure, Jamestown and Leeds. 



Munroa squarrosa (Nuttall) Torrey. This plant was found near 

 Wanitah Lake, Foster Co. (No. 387, Aug. 22, 1917, D. C. Mabbott), 

 much farther east than hitherto reported. Previously it has not been 

 observed east of the Missouri River, the only two localities known in 

 the state being Mandan and Medora, west of the Missouri River 

 (Bergman). 



Sphenopholis ohtusata (Michx) Scribner var. lohata (Trinius) Scribner. 

 Not previously recorded from the state. Frequent ; Bergman considered 

 all the material collected as the true species ohtusata; all the plants col- 

 lected by the writer were clearly the variety lohata; Buckhouse Slough, 

 Richland Co. (No. 94 and No. 116, July 23, 1917); Moon Lake, Barnes 

 Co. (No. 212, Aug. 3, 1917, D. C. Mabbott). 



Scolochloa festucacea (Willdenow) Link. Very common throughout 

 the state; the characteristic grass of Mallard Slough; reported from over 

 twenty-one counties. Bergman lists this plant only from Fargo, 

 Valley City and Ft. Totten. 



Cyperus diandrus Torrey. Not previously reported in the state, 

 considered here to be at the extreme western border of its range. Found 

 only along border of Moran Lake, Richland Co. (No. 182, July 27, 



1917). 



Scirpiis occidentalis (Watson) Chase and Scirpus Validus Vahl. 

 The former is abundant throughout the state in marshes and sloughs, 

 and the latter frequent but not clearly distinguishable from 5. occi- 



