56 



than 3 or 1 inches above the ground, growing in extensive tufts or 

 patches, and spreading largely by means of stolons or offshoots similar 

 to tbose of Bermuda grass, these stolons being sometimes 2 feet long, 

 and with joints every 3 or 4 inches, frequently rooting and sending np 

 flowering culms from the joints. The leaves of the radical tufts are 3 

 to 5 inches long, one or one half line wide, smooth, or edged with a few 

 scattering hairs. The flowering culms are chiefly dioecious, but some- 

 times both male and female flowers are found on the same plant but in 

 separate parts. Next to the grama-grass it is perhaps the most valua- 

 ble grass in the support of the cattle of the plains. (Plate IS.) 



THoclia trim. erviglwm is (Spear-grass). 



Another perennial species, growing in Colorado, Arkansas, Texas, 

 Xew Mexico, and southward. The culms are 2 to 3 feet high, and rather 

 stout ; the radical leaves are somewhat rigid, G to 12 inches long, nar- 

 row, acuminate-pointed, inclined to be involute, the sheaths more or 

 less hairy. The smooth culm has three or four leaves, which are 4 to 8 

 inches long and slender-pointed. Little is known of its abundance or 

 agricultural value. (Plate 19.) 



Triodia acuminata (White tuft-grass). 



A low species, growing in tufts from G to 12 inches high, the leaves 

 short and narrow, but abundant near the ground; the culms are erect, 

 slender, with one or two short leaves, and terminated by an oblong, 

 spike-iike panicle about an inch long, composed of a few crowded ses- 

 sile or nearly sessile branches, each with one to three spikelets. The 

 spikelets each contain eight or ten crowded flowers. This is a native of 

 the arid regions of Texas, Xew Mexico, and southwestward. (Plate 20.) 



Diplacline fascicular is (Spike-grass). 



An annual grass of vigorous growth, 2 to 3 feet high, growing in brack- 

 ish marshes or wet ground near the sea-coast, and also far inland in the 

 Mississippi Valley, Texas, Arizona, etc., in alkaline soil. The radical 

 leaves are narrow and half to two-thirds as long as the culms, rough 

 on the margin ; those of the culms similar, with long, smooth loose 

 sheaths, the upper ones usually inclosing the base of the panicle. The 

 culms are frequently branched at the lower joints. The panicle is large, 

 G to 10 inches long, consisting of numerous (fifteen to thirty) spike-like 

 branches, which are 2 to 1 inches long, mostly alternate, sometimes 

 fascicled below, angular and rough, and flower-bearing throughout. 

 (Plate 21.) 



})i pi acinic dubia. 



A grass of similar aspect to the preceding; the leaves somewhat 

 longer and more rigid ; the panicle rather shorter, and composed of 

 six to twelve branches, which are stouter and more spreading. The 

 spikelets in age become spreading, and the axis zigzag. It is of more 

 southern range than the preceding, occurring iu the Gulf States and 

 southwestward. (Plate 22.) 



