1912] GLEASON & GATES—RATES OF EVAPORATION 483 
other species. Scattered among the grasses are plants of several 
secondary species which fill the spaces between the bunches and 
give the area the appearance of a closed association. The more 
prominent of these are Lespedeza capitata, Opuntia Rafinesquit, 
Crotonopsis linearis, Ambrosia psilostachya, Oenothera rhombipetala, 
Lepidium virginicum, Krigia caroliniana, Cyperus Schweinitzit, 
‘+ 
Fic. 2.—The center of a willow island, To atmometer no. r on a maple 
stump, July 9, 1910; photograph by F. 
Specularia perfoliata, Croton glandulosus, Erigeron canadensis, 
ommelina virginica, Monarda punctata, Callirhoe triangulata, 
Carex Muhlenbergii, and Erigeron strigosus. 
The Leptoloma consocies, which is very abundantly represented 
in this region, is a less stable type of bunch-grass. The dominant 
species, Leptoloma cognatum, does not form bunches as well defined 
as those of Eragrostis trichodes, but with its spreading habit and 
irregular bunches occupies a larger proportion of the area. With 
it are associated a few other grasses, especially Panicum pseudo- 
