46 



THE TRIBES AND THEIR GENERA. 



Agrostis alba. 

 Floret. For Spikelet see p. 67. 



hyaline, generally with a dorsal awn. 

 Inner palea short and small, or absent. 

 Stamens three. Stigmas pectinately 

 branched, usually protruding from sides 

 of spikelets. Grain enveloped by jpaleae, 



Species. A. alba, 26. 

 A . canina, 27 

 A. setacea, 28, 

 A. spica-venti, 29. 



Gastridium. Panicle dense, spike-like, 

 spikelets narrow and shining. Rachilla 

 extending beyond palese. Glumes persistent, 

 unequal, swollen at base, acute, smooth, 

 shining. Outer palea a third as long as 

 glumes, thin. Stamens three. Stigmas 

 pectinately branched, usually protruding 

 from sides of spikelets. Grain enveloped by 

 paleae. 



Species. G. lendigerum, 30. 



Gastridin m lendiger urn. 



Floret. 

 For Spikelet see p. ior. 



Calamagrostis. — Panicle variable. Rachilla extending be- 

 yond paleae. Glumes persistent, nearly equal, keeled. Outer 



palea thin, membranous, narrow, 

 short, awned. Stamens three. 

 Stigmas pectinately branched 

 and usually protruding from 

 sides of spikelets. Grain en- 

 veloped in paleae. Broader 

 leaves twisted to the left. 



Species. 



Calamagrostis epigeios. 

 Floret. For Spikelet see p. 89. 



C. epigeios, 32. 

 C. lanceolata, 33 

 C. stricta, 34. 

 C. strigosa, 35. 



