336 GRASS ORDER 



(a) Spikelets 2-many-flowered, the glumes 



lanceolate Elymus 



(b) Spikelets 1 -flowered, the glumes awl- 



shaped and in a row Hordeum 



2. Spikelets not in 2 rows in a one-sided or zig-zag 

 spike 

 a. Spikelets 2-many-flowered 



(1) Lemma awned from the back 



(a) Spikelets less than 1 cm. long 



x. Lemma fringe-toothed or 2-toothed at * 



tip Deschampsia 



y. Lemma 2-cleft at tip, the teeth awn- 

 pointed 

 (x) Awn bent and twisted Trisetum 



(y) Awn straight or none Graphephorum 



(b) Spikelets more than- 1 cm. long A vena 



(2) Lemma awned from the tip or awnless 



(a) Plants dioecious; lemma 3-awned Scleropogon 



(b) Plants not dioecious; lemma entire or 



2-lobed 

 x. Hairs very long and enclosing the lem- 

 ma; tall swamp grasses Phragmites 

 y. Hairs none or shorter than the lemma 

 (x) Spikelets in the axils of spiny 

 leaves ; stems spreading, 1-4 in. 

 high Munroa 

 (y) Spikelets not in the axils of spiny 

 leaves 

 m. Lemma 1-3-nerved 



(m) Lateral nerves of the lemma 

 hairy 

 r. Spikelets appressed on the long 



branches of a panicle Diplachne 



s. Spikelets not appressed on long 



branches Triodia 



(n) Lateral nerves not hairy 

 r. Lemma copiously long-hairy at 



base Redfieldia 



s. Lemma not long-hairy at base 

 (r) Upper glume much broader 



than the lower Eatonia 



