THE TRIBES AND THEIR GENERA. 



47 



Psamma. Panicle spike-like, nar- 

 row, cylindrical. Spikelets rather 

 large. Rachilla extending beyond 

 paleae. Glumes persistent, stiff. 

 Paleae chartaceous. Outer palea thin, 

 somewhat indurated, awnless. Inner 

 palea with two ribs. Stamens three. 

 Stigmas pectinately branched, usually 

 protruding from sides of spikelet. 

 Grain enveloped in paleae. 



Species. P. arenaria, 31. 



Psamma arenaria. 

 Floret. For Spikelet see p. 135. 



Lagurus. Panicle spike-like or capitate. Spikelets very 

 hairy. Glumes persistent, long, narrow, spreading, bearing 

 plumose hairs. Outer palea firm, shorter 

 than glumes, with two awns forking from its 

 apex and a long dorsal awn. Inner palea 

 shorter than outer, with two ribs, a pair 

 of awns at its apex, smaller than those 

 of the outer palea. Lodicules lanceolate, 

 blunt, tumid at base. Stamens three ; 

 filaments capillary, anthers oblong, pen- 

 dulous, notched at each end. Ovary ob- 

 long ; styles short. Stigmas long, pecti- 

 nately branched and protruding from 

 sides of spikelet. Grain enveloped in 

 paleae. 



Lagurus ovatus. x 



Floret. Species. L. ovatus, 23. 



For Spikelet see p. 107. 



AVENE^E. 



Florets three or more. 

 Florets two. 



Both florets perfect. 



Upper floret perfect. 



Lower floret perfect. 



A vena, 41-43. 



Air a, 36-40. 

 Arrhenatherum, 10. 

 Holcus, 45, 46, 



