Hairy grama, an erect, rigid perennial, occurs from British Co- 

 lumbia to Illinois, Texas and California and south into Mexico; 

 also, along the Gulf Coast, to the pinelands of peninsular Florida. It 

 is one of the two or three most widely distributed species of grama. 

 It is named hirsuta (hairy) because of the hairy spikes and because 

 the margins of the leaves typically, although not invariably, bear 

 rather long, scattered hairs. However, the chief distinguishing 

 feature is that the spike axis projects as a naked point beyond the 

 uppermost spikelet. 



This grass occurs chiefly on dry, sandy and sandy loam soils, oc- 

 casionally up to 8,000 feet, though rarely above elevations of 7,000 

 feet, and, in southern Arizona, attains most satisfactory develop- 

 ment upon stable sandy loams at elevations between 4,000 and 6,000 

 feet. It is often associated with blue grama but is more drought- 

 resistant and frequently grows at lower altitudes and on less favor- 

 able sites. It occurs over much of the Southwest, especially in 

 southern Arizona, and is one of the outstanding grasses of that 

 region, being seldom found in pure stands but often appearing 

 abundantly in mixture with side-oats grama (Bouteloua curtipen- 

 dula), slender grama (B. filiformis), other gramas (Bouteloua spp.), 

 cane beardgrass (Andropogon barbinodis) , mesquites (Prosopis 

 spp.), and catclaw (Acacia greggii}. Hairy grama is very abundant 

 in the sandy soils along the more southern portions of the Texas- 

 New Mexico State line where, with a few species of beardgrasses 

 (Andropogon spp.), it constitutes about the only forage and, on the 

 plateau of central Mexico, it grows in practically pure stands. 1 



Hairy grama has about the same palatability as blue grama, con- 

 stituting very good forage especially for winter use, but ordinarily 

 it is a smaller plant and produces less forage. It withstands grazing 

 very well, but, like most other gramas, does better if it is grazed 

 lightly during the summer growing period, leaving most of the 

 crop, which cures very well on the ground, for use during fall, 

 winter, and spring. Little growth is made until after the summer 

 rains begin but, if precipitation then is adequate, the species matures 

 rapidly. During exceptionally dry years this grass produces very- 

 little forage, although it withstands such droughts remarkably well. 



Hairy grama is variable in size and appearance. In the northern 

 part 01 its range this species usually has only one or two spikes 

 on a stalk and has short rootstocks (rhizomes) which tend to form 

 a sod, but in the South it grows in clumps, closely resembling a 

 bunchgrass, and often has from two to four spikes on each culm. 

 The spikes are often purplish and are % to V/$ inches long. The 

 leaves are flat and narrow, and are more numerous on the lower than 

 on the upper portions of the stem. 



1 Griffiths, D. THE GRAMA GRASSES : BOUTELOUA AND RELATED GENERA. U. S. Natl. Mus., 

 Contrib. U. S. Natl. Herb. 14 : 343-444, illus. 1912. 



