130 



Fig. 99. Triplasis americana Beauv. — a, A spikelet; &, a joint of the rachilla 

 and floret, showing the palea. Fig. 509 in Bui. 17 illustrates a second species of 

 this genus. 



99. TRIPLASIS Beauv. Agrost. 81, t. 16, f. 10. 1812. (Diplocea Rafin. 1819.) 

 Spikelets many-flowered; flowers hermaphrodite or the uppermost staminate. 

 Empty glumes 2, carinate, acute, awnless, shorter than the others; flowering 

 glumes distichous along the rachilla, rounded on the back at the base, deeply 

 3-lobed, lobes smooth or ciliate, sides narrow, very acute, almost produced 

 into awns, the middle longer, aristiform, often subflexuous-spreading. Palea 

 shorter, broad, compressed, 2-keeled, keels long-ciliate. Stamens 3. Stylesshort, 

 distinct; stigmas plumose. Perennial grasses, with very narrow leaves, convo- 

 lute or flat at the base; and slender simple panicles; spikelets shortly pedicel- 

 late, usually erect. 



Species 2, North American. 



