982. 
20 t 
a. Agrostis L. Bentgrass. / 
Perennial grasses with open or contracted panicles fof small 
spikelets. Spikelets 1-flowered, disarticulating above glumes, the 
rachilla not prolonged behind the palea, prolonged in A. hurberiana; glumes 
nearly equal, acute or acuminate; lemmas obtuse, thinner in texture and shorter 
than the glumes, sometimes hairy on the callus; palea usually reduced to a 
small nerveless scale. 
O Rachilla prolonged behind the palea 1X, ie ee 
Oo Rachilla not prolonged 
& Palea present, more than half as long as the athea 
6 lemma oe Ae palustris 
2 Palea wanting or a small nerveless scale 
4 ihizanes present de Ae diegoensis 
4 Rhizomes wanting 
& Panicles aittuso[ the Spikelets clustered 
/ toward the ends of the Slender, very scabra 
fo \ scabrous branches 4. Ae Riometis. 
io Panicles often loose but not diffuse, the 
‘© branches relatively short 
8 Panicles dense, the branches spikelet- 
12 bearing from the base; glumes scabrous on 
the back O- Ae exarate 
8 Panicles loose, the branches naked below; 
/ Slumes glabrous on the back, scabrous on 
AN the keel 
/0 Culms delicate, less than 40 cme tall; 
] rox 
° jo) 
/A svikelets 1.5=2 mn, Ge As idahoensis 
/o Culms slender but not delicate, more 
’ cnan 40 ome tall; Spikelets 2.5-3 mm. 
" long (eo Ae Orezononsis 
