GRAMINEAE 



culate: habit various: infl. an open or contracted panicle, sometimes an open or spike- 

 like raceme. 



8. Cleistogenes 



Molinia 



Moliniopsis 



Eragrostis 



Lophatherum 



Key to the Genera 



A. Lemma or rachilla with long silky hairs. 



Lemmas glabrous, awnless; rachilla segments not jointed, with 



hairs exceeding the lemma 6. P/iragmites 



Lemmas densely long-pilose on the margins, the apex with a 



recurved awn; rachilla in 2 segments, articulate 7. Neyraudia 



AA. Lemma and rachilla glabrous, or if pubescent, the hairs short. 



B. Lemmas 3-1-nerved (5-3-nerved in Cleistogenes); the nerves 

 usually prominent. 

 C. Cleistogamous spikelets present within the sheaths: 



lemmas awned or mucronate 



CC. Cleistogamous spikelets wanting: lemmas awnless. 

 Lemmas subterete. 



Rachilla glabrous or sparsely pubescent 9. 



Rachilla densely silky-pubescent 10. 



Lemmas compressed; rachilla glabrous 11. 



BB. Lemmas several-5-nerved; the nerves sometimes obscure. 



D. Lf. blades broad, lanceolate or ovate, transversely 



veined 12. 



DD. Lf. blades usually narrow, linear, not transversely 

 veined. 

 E. Spikelets in dense one-sided clusters on the ends 

 of the few stiff branches of an open pan- 

 icle 19. Dactylis 



EE. Spikelets not crowded (except in Puccinellia ken- 

 giana), arranged in open or contracted panicles 

 or racemes. 

 F. Lemmas as broad as long; the margins out- 

 spread; florets closely imbricate, horizon- 

 tally spreading 20. Briza 



FF. Lemmas longer than broad; the margins clasping 

 the palea; florets not horizontally spread- 

 ing. 

 G. Spikelets jointed with and falling off from 



the curve of the pedicels 21. Melica 



GG. Spikelets not jointed with the pedicels, 

 but disarticulating above the glumes. 

 H. Nerves of the lemma parallel, not 

 converging at the summit or but 

 slightly so; lemmas awnless, mostly 

 obtuse. 

 Nerves prominent; styles distinct .. 13. 



Nerves faint; styles none 14. 



HH. Nerves of the lemma converging at 

 the summit; lemmas awned or 

 awnless. 

 I. Spikelets awnless; the lemmas more 



or less cobwebby at the base. . 15. Poa 

 II. Spikelets awned or awnless; the 

 lemma never cobwebby at the 

 base. 



440 



Glyceria 

 Puccinellia 



