PLANTS OF THE FLORISSANT REGION IN COLORADO 1 83 



is to be expected because the aspens occur in the richer and more moist 

 soil, and they furnish shade which is suitable for certain plants. Vio- 

 lets, Arnica, the columbine, larkspurs, the false Soloman's seal, and 

 other shade-plants occur here. 



Even a short account of the Florissant region should contain some 

 mention of the grasses found there. Of these there are many species, 

 but few individuals of any one kind. Nowhere is there a grass carpet 

 of any size, and the grasses occur almost always in small clumps widely 

 scattered on hillsides and stream banks. As is usual in Colorado, 

 the wheat grasses, wild barley, fescue, grama grass, and bromes 

 are the kinds most abundant, rather than such forms as panic grass 

 and blue grass, which arc so widely distributed and so abundant in 

 the eastern United States.^ 



In the Florissant region, as elsewhere in the mountain districts 

 of Colorado, the plant population is of a mixed character. The bril- 

 hant sunshine, long continued through the growing season, permits 

 the growth of southern forms and plants of the plains region. At 

 the same time, in shady situations among rocks and on north slopes, 

 it is likely to be cool even in the warmest part of the summer. Thus, 

 northern plants are able to obtain a foothold. On the whole, how- 

 ever, the afl&nities of the flora are with the South rather than with the 

 North. The flat, open parts of the lake basin furnish conditions suited 

 only to a few species of xerophytic plants, but these are represented 

 by many individuals. Many more species are found on the dry hill- 

 sides; but it is only along moist canyon-sides and stream-banks that 



' Seventeen species of grasses were collected. They have been determined by Professor Aven Nelson. 

 Following is the list: 



Agropyron caninum (Linn.) Beauv. Bromus porteri lanatipes Shear 

 Agropyrondasyslachyumsubvillosum(Rook.)Z.&L?i. Bromus pumpellianus Scribn. 



Agropyron occidentale (Vasey)Shear Danthonia parryi Scribn. 



Agropyron pseitdorepens S. & S. Fesluca ovina Linn. 



Agropyron tenerum Vasey Hordeum nodosum Linn. 



Agropyron spp. Koeleria cristata (Linn.) Pars. 



Bouteloua oligostachya (Nutt.) Torr. Sitanion longijoUus J. G. Smith. 



Bromus porteri (Coult.) Nash Stipa vaseyi Scribn. 



