APPENDIX. 
The native grasses occupying that portion of the arid region here in- 
vestigated are numerous, but only two kinds play the most important 
part in the support of animal life. These are, botanically, Bouteloua 
oligostachya and Buchloe dactyloidoe, commonly called gramma-grass and 
buffalo grass, respectively, but frequently called indiscriminately buf- 
falo-grass. They are of low growth, forming patches of greater or 
less extent, with spaces of bare soil between the patches. The leaves 
are short and mostly crowded close to the ground. There are several 
species of Bouteloua or gramma-grass, but the one above named is the 
principal one on the great stretches of upland. The others occur lo- 
cally, some on rocky ridges and some in what is called bottom land. 
In valleys and bottoms near the mountains the dwarf gramma-grass, 
Bouteloua prostrata, often carpets the ground over large areas. This 
extends, at least, from Northern Colorado to Santa Fe, N. Mex. The 
common gramma varies much in size and vigor, according to its loca- 
tion. In rich moist bottom land it may grow 2 feet high and form a 
pretty close sod, but on the elevated dry plains it becomes greatly re- 
duced in size and productiveness. Wherever it is not too closely 
cropped by cattle it seeks to send up its flowering stalks, sometimes not 
more than 6 inches high, but usually a foot or more. Near the top of 
the slender stalk are from one to two, or rarely three, flower-spikes, 
which when mature stand out nearly at right angles, and are an inch to 
an inch and a half long, with the flowers all arranged on one side of the 
spikes. 
The true buffalo-grass, Buclilce dactyloides, forms extensive cushion- 
like beds, covering the ground closely with its short, compact foliage, 
which is of a lighter color than the gramma. This grass is very pecul- 
iar in one respect. It is of a dioecious habit — that is, the two sexes 
grow on different plants, or if on the same plant they are not on the 
same stalk. Usually, however, they are wholly distinct and in different 
patches. The male spikes resemble in appearance those of the gramma, 
but are much smaller, and the stalks never grow tall. The female flowers 
are inconspicuous, generally being concealed among the leaves near the 
ground, and seed is rarely formed, the plant being mainly propagated 
by its short-jointed, creeping runners, after the manner of Bermuda- 
grass. According to my observation the gramma- grass is much the 
most common, but the two are generally associated in varying propor- 
tions, but together forming from 75 to 90 per cent, of the whole grass 
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