STANDLEY FLORA OF GLACIER PARK. 281 



Panicles cylindric or nearly so, dei^se, spikelike. Glumes exceeding the 

 florets. 

 Glumes awn-tipped, stiffly ciliate on the keel; panicle harsh to the 



touch 7. PHLEUM. 



Glumes not awn-tipped, silky-ciliate on the keel; panicle soft and 



silky to the touch 8. ALOPECURUS. 



Panicles open or contracted, but not subcylindric. 

 Glumes shorter than the floret. Panicle very slender, contracted ; plants 



low and wiry 6. MITHLENBERGIA. 



Glumes as long as the floret or exceeding it. 



Spikelets falling entire; panicle open, drooping. Florets without 



silky hairs at base 9. CINNA. 



Spikelets not falling entire, the florets falling from the persistent glumes. 

 Florets without silky hairs at base or with very obscure ones. 



10. AGROSTIS. 

 Florets with copious silky hairs at base; lemmas awned from the 



back 11. CALAMAGROSTIS. 



Spikelets 2 to many-flowered. 

 Glumes equaling or exceeding all the florets; lemmas awned from the back 

 or from l)etween the teeth of the prominently 2-toothed apex (the awn 

 often obsolete in Trisetum wolfii). 

 Spikelets not over 8 mm. long; awn delicate. 

 Lemmas rounded on the back, dentate at the broad summit . 12. AIRA. 

 Lemmas keeled on the back, the apex acute, 2-toothed . 



13. TRISETUM. 

 Spikelets 12 mm. or more long; awns stouter. 



Spikelets about 3 cm. long; lemmas over 12 mm. long, awned from the 



back, the awn not flattened 15. AVENA. 



Spikelets mostly 12 to 15 mm. long; lemmas not over 8 mm. long, awned 

 from between two long teeth, the awn flattened and twisted below. 



16. DANTHONIA. 

 Glumes not exceeding the lowest floret; lemmas awnless or awned from the 

 apex or from just below it. 

 Lemmas broad at the summit, the nerves not converging at the apex, 

 Spikelets 2-flowered; lemmas prominently 3-nerved. 



18. CATABROSA. 

 Spikelets 4 to 8-flowered; lemmas 5 to 7-nerved. 



Lemmas indistinctly nerved 23. PUCCINELLIA. 



Lemmas very strongly nerved 22. PANICTJLARIA. 



Lemmas acute, pointed or awned, the nerves converging toward the apex, 

 liemmas keeled on the back, awnless. 

 Spikelets 10 to 15 mm. long; lemmas firm, finely and obscurely many- 

 nerved; plants dioecious 20. DISTICHLIS. 



Spikelets mostly less than 8 mm. long; lemmas membranaceous, 

 5-nerv'ed; spikelets perfect. 

 Second glume noticeably larger than the first; culm pubescent 

 below the panicle; blades not boat-shaped at -the tip. 



14. KOELERIA; 

 Second glume scarcely larger than the first; culm not pubescent. 



blades boat-shaped at the tip 21. POA. 



Lemmas rounded on the back, or slightly keeled toward the summit 

 only, awned or awnless. 



