56 
than 3 or 4 inches above the ground, growing in extensive tufts or 
patches, and spreading largely by means of stolons or offshoots similar 
to those of Bermuda grass, these stolons being sometimes 2 feet long, 
and with joints every 3 or 4 inches, frequently rooting and sending up 
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 
seattering 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 ofthe plains. (Plate 18.) 
Triodia trinerviglumis (Spear-grass). 
Another perennial species, growing in Colorado, Arkansas, Texas, 
New Mexico, and southward. The culmsare 2 to 3 feet high, and rather 
stout; the radical leaves are somewhat rigid, 6 to 12 inches long, nat- 
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 
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 6 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-like 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. Thisis a nativeof 
the arid regions of Texas, New Mexico, and southwestward. (Plate 20.) 
Diplachne fascicularis (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, ete., 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, 
6 to 10 inches long, consisting of numerous (fifteen to thirty) spike-like 
branches, which are 2 to 4 inches long, mostly alternate, sometimes 
fascicled below, angular and rough, and flower-bearing throughout. 
(Plate 21.) 
Diplachne 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, oceurring in the Gulf States and 
southwestward. (Plate 22.) 
