97 



Tribe X.— CHLORIDES. 



Spikelets 1-to several-flowered in 1-sided spikes or racemes; 

 the racemes digitate or fasiculate, rarely solitary; flowering glumes 

 usually keeled, entire and unawned, or toothed, and with 1 or 3 

 (rarely more than 3) straight awns. 



A small tribe of 27 genera and 155 species, charac- 

 terized chiefly by the inflorescence, which is nearly that 

 of Paspalum. The awns when present, are not dorsal 

 or twisted, as in the Agrostidew and Avenece. Chiefly 

 natives of tropical and subtropical countries ; a few are 

 widely distributed- as weeds throughout the warmer 

 parts of the world. A number are good turf-forming 

 grasses and are yalued for grazing purposes. One of 

 these is the celebrated buffalo-grass of the Western 

 plains, which is remarkable for having the staminate 

 and pistillate spikelets separate and in unlike inflores- 

 cences, either upon the same plant (monoecious) or 

 upon different plants (dioecious). Bermuda-grass, and 

 the Gramas Of the South West belong to this tribe. 



KEY TO THE GENERA OF THE CHLORIDES. 



1. Spikelets unisexual, dissimilar, the staminate and pistillate 

 spikelets on the same, or on separate plants.. 85. Bulbilis 



1. Spikelets all alike, hermaphrodite 2 



2. Spike solitary; second empty glume with a stout, divergent 



awn on the back near the middle 75. Campulosus 



2. Spikes rarely solitary; empty glumes not awned on back 3 



3. Spikelets articulated with the pedicels below the empty 



glumes 4 



3. Spikelets not articulated with the pedicels; empty glumes per- 



sistent 5 



4. Spikelets strongly compressed; empty glumes unequal keeled. 



74. Spartina 



4. Spikelets not much flattened; empty glumes equal, inflated 



and rounded on the back 81 . Beckm annia 



5. Spikelets strictly 1-flowered, without any prolongation of the 



rachilla, or, if prolonged, reduced to a simple rudiment with- 

 out bracts or awns 6 



5. Spikelets 2- to several-flowered, or with an awned, or bracteate 



prolongation of the rachilla 7 



15444— No. 20 7 



