METCALP: NOTES ON NORTH DAKOTA PLANTS I91 



definite ecological conditions such as are afforded by sand hills, 

 swampy bogs or fresh water all of which are only occasionally 

 or locally found in the state. 



The second group, namely, plants of imperfectly known dis- 

 tribution is taken up in detail in the subjoined list; here also 

 will be found complete data for all plants mentioned in this ar- 

 ticle, with actual citations of specimens collected. It may be 

 well to add that all specimens collected by D. C. Mabbott are so 

 labeled; the others recorded were obtained by the writer. All 

 specimens have been placed in the U. S. National Herbarium 

 at Washington. 



There is no doubt in the writer's mind that the number of new 

 plants added by this paper to the flora of North Dakota is small 

 in comparison with the number that will be found upon further 

 collecting. North Dakota is a great field for intensive botanical 

 field investigation especially in working out interesting problems 

 in eastern and western distribution. 



Grateful acknowledgement is hereby made to Carleton R. 

 Ball of the U. S. Department of Agriculture, for determinations 

 of species of Salix and to W. L. McAtee for assistance and timely 

 suggestions. 



LIST OF PLANTS 



Sparganhim antencannm Nuttall. Not previously recorded from 

 the state. Range here greatly extended westward as formerly unknown 

 west of Iowa. Rather common in Riverside Marsh, Mandan, Morton 

 Co. (No. 377, Aug. 27, 1917), and frequent along border of Bismarck 

 Slough, Burleigh Co. 



Potamogeton Friesii Ruprecht. Lunell^ reports this from "Jamestown 

 in James River and Lake Ibsen (extinct)." Bergman, however, does 

 not give this record. Found only in Upsilon (No. 479, Sept. 8, 1917, 

 D. C. Mabbott) and Jarves Lakes, Rolette Co., in the Turtle Moun- 

 tains. 



Potamogeton heterophyUus Schreber. Found abundantly in Bismarck 

 (No. 355, Aug. 24, 1917) and King (No. 345, Aug. 24, 1917) Sloughs, 

 Burleigh Co.; Max Slough and Big Slough (No. 471, Sept. 6, 1917), 

 near Underwood, McLean Co. Bergman reports this plant from four 

 localities (Kulm, Spiritwood, Leeds and Wahpeton). 



Potamogeton natans Linnaeus. Frequent throughout the Turtle 

 Mountains, rare elsewhere. Bergman reports this only from Lake 



5 LuNELL, J. "Enumerantur Plantae Dakotae Septentrionalis Vasculares." 

 Am. Mid. Nat. 4-5: July, 1915-July, 1917. 



