IMPORTANT RANGE PLANTS. 5 



KEY TO THK TRIBES AND GENERA. 

 KEY TO THE TRIBES. 



A . Spikelets upon pedicels in open or spikelike panicles, not in rows. 



B. Spikelets with but 1 perfect flower (the rachilla prolonged behind the palea as 

 a bristle in Calarnagrostis and Cinna) .................... Tribe Agrostideae. 



B. Spikelet.s with 2 or more perfect flowers. 



('". Glumes usually longer than the first floret; florets with bent awn on the back 

 (excepting Koeleria} .................................... Tribe Aveneae. 



c. Glumes much shorter than the first floret, unawned or with a straight awn 

 from the apex ....................................... Tribe Festuceae. 



A. Spikelets sessile, in opposite rows along a zigzag jointed rachis forming a spike; 

 leaf blades bearing a pair of earlike appendages at the base ...... Tribe Hordeae. 



KEY TO THE GENERA. 



Agrostideae. 



A. Lemmas hardened, having a needlelike point at base and a long, usually twice 

 bent awn at the summit ........................................ Genus Stipa. 



A . Lemmas thin and delicate, not needle-pointed at base, awn less or with a minute 



awn from the back. 

 B. Spikelets in a dense spikelike head: glumes abruptly awn-tipped. 



Genus Phleum. 

 B. Spikelets in open or narrow panicles; glumes not awn tipped. 



C. Floret raised on a little stalk: spikelets in a large nodding panicle. 



Genus Cinna. 

 r. Floret sessile. 



D. Floret bearing at base copious white hairs sometimes as long as the 

 lemma; rachilla extended behind the palea ..... Genus Calamagrostis . 



D. Floret naked or nearly so; rachilla not extended behind the palea, the 

 latter often wanting ............................... Genus Agrostis. 



Arcneae. 



A. Lemmas awned. 



' B. Panicles open; lemmas convex, irregularly toothed or 2-lobed, awns arising 

 from below the middle ................................ Genus Deschampsia. 



B. Panicles narrow or spikelike; lemmas keeled, 2-toothed, the awn arising from 

 above the middle ....................................... Genus Trisetum. 



A . Lemmas not awned, panicles spikelike, culms pubescent below panicle. 



Genus Koeleria. 



A. Spikelets with upper florets usually sterile, broad and folding about each other, 

 forming a club-shaped mass; glumes shining; lemmas papery, scarious margined. 



Genus Melica. 

 A. Spikelets with upper florets not unlike lower ones in shape, but often reduced in 



size. 

 B. Spikelets not over 5 mm. ($ of an inch) long; not awned. 



C. Lemmas keeled, acute, the nerves not prominent ............... GenusPoa. 



C. Lemmas convex, obtuse, the nerves prominent ......... Genus Panicularia. 



B. Spikelets 1 cm. (f of an inch) or more long, awned or awn-pointed. 



D. Lemmas 2-toothed, usually awned just below the apex ___ Genus Brornus. 

 D. Lemmas entire, usually awned from the tip ............. Genus Festuca. 



