04 Xoff's on flic Flora of Dakota ami Montana — Leiherg. 



water-courses. The extreme dryness of these hot winds is reniark- 

 jibh?. During the great heat whicli prevailed in the early part of 

 July, I saw tlie grass on the prairie, which was green and fresh as 

 prairie grass usually is, completely dried up and converted into 

 hay within a period of two hours. As a consequence of this dry 

 w^eatlier, we find no annuals in summer. They only appear dur- 

 ing the spring, while the ground is still uu)ist. The perennials 

 all have long root-stocks, which penetrate deeply into the ground 

 and enable them to withstand the drouth effectually. 



The surface of the country west of the Red river valley, is 

 more rolling than in Minnesota, and is found still more so as the 

 Missouri river is approached. Numerous stony kncdls and loug 

 ranges of rocky, pointed hills mark the ancient glacial moraines. 

 The flora here shows plain indications of the proximity of the dry, 

 treeless plains west of the Missouri: though at the same time the 

 climate is humid enough to permit species of plants to grow and 

 flourish, whose principal habitat is much farther eastward. Here 

 and there alkaline pools appear with their peculiar plants, adding 

 largely to the variety of the flora of this regi(m. Many species 

 are found whose home in the Southwest is at a high elevation, 

 proving that as we go north the increase in latitude compensates 

 for a decrease in elevation. 



Scattered over the drift hills in great abundance, and tlr? first 

 flovser to appear in spring is Anemone pafens. L , var. Nutfaliana. 

 Gray, attaining a luxuriance of growth never met with in Minne- 

 sota. After crossing the Missouri and the western boundary of 

 the glacial drift, this plant wholly disappears. In the moist places 

 of the prairies is found RannncHlns(ilaher)-iinns^ Hook., and around 

 alkaline ponds U. Cfjmhalaria, Pursh, the latter being very abun- 

 dant west of the Missouri river. Another representative of this 

 genus resembles B. rhonihoidens. Goldie, but difl'ers from that in 

 its more errect and taller growth and much smaller flowers. It 

 appears to be some undescribed species. 



A Draba^ probably 1). nentorofia, L., is quite plentiful. Early 

 in the spring, and flowering until late in the summer, we find 

 Vesicaria Lndot'iciana, DC. Erf/shnun) asperuin^ DC, is abund- 

 ant as we proceed westward, becoming a very conspicuous plant. 

 Around the alkaline ponds grows a Xasfurfium near N. xinnainnK 

 Nutt. It may prove to be only a variety of this species. 



Cleome integrifolia. Torr. & Gr., which is found here and 



