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ARISTIDA ARIZONICA.—Culms 1 to 2 feet high, tufted, 
rigidly erect, unbranched, leafy to the middle, smooth; leaves of 
the culm about four, of nearly equal length, 4 to 8 inches long, 
-canaliculate or becoming convolute, narrow and somewhat rigid, 
smooth; panicle 5 to 10 inches long, narrow; the branches in twos 
below, appressed, somewhat distant (the lower internodes 2 to 
3 inches long), unequal, the longer one overlapping the inter- 
node above, and naked below, the shorter one sessile, each with 
two to eight short pedicelled spikelets; outer glumes nearly 
equal, 6 to 7 lines long, bidentate at the apex, mucronate or awn 
pointed, hispid on the keel, one-nerved or the lower three-nerved ; 
flowering glume to the division of the awn and including the short 
hairy callus, 7 to 8 lines long, slender, smooth below, scabrous 
and twisted above, the awns nearly equal, 10 to 12 lines long, 
widely divergent when mature. This species differs from Avzs- 
tida purpurea, Nutt., ina more rigid habit, longer leaves, more 
erect and rigid panicle, and especially in the comparative length 
of the glumes (in A. purpurea, lower glume is only about half as 
long as the upper); in the longer flowering glume, (in A. pur- 
purea the upper glume considerably exceeds the flowering one), 
and in the shorter awns. Collected in Arizona. on. 
ARISTIDA HAVARDII.—Culms about 1 foot high, slender, 
leafy; leaves setaceous, erect, 3 to 5 inches long, the upper one 
enclosing or near the base of the panicle; panicle 5 to 6 inches 
long, somewhat pyramidal; branches mostly in twos, unequal, 
almost capillary, spreading and sometimes reflexed, the longest 
about 2 inches long, loosely flowered, the lower part (4% inch) | 
naked; spikelets pedicelled; outer glumes nearly equal, 4 to 5 
lines long, narrow, one-nerved, acuminate, the upper a little | 
longer than the flowering glume, including the short obtuse hairy - 
callus; the flowering glume smooth below, spotted, and tapering 
to the scabrous apex, awns erect-spreading, nearly equal, about — 
6 to 8 lines long. ; 
This has somewhat the appearance of A. divaricata, but is 
much smaller, and without the long naked branches of that spe- 
cies. Collected in Western Texas by Dr. Havard. 
ARISTIDA ORCUTTIANA.—Culms about two feet high, stout _ 
below, above becoming slender, very leafy; leaves near the base 
