CVn. GRAMINE^:^ 527 



J 



29. Dactylis. Panicle with the secondary branches short and very 



dense, subsecund. Spikelets with 3 — "4: perfect florets, compressed. 

 Glumes shorter than the florets, unequal ; outer one keeled. Outer 

 glumella keeled and ciliated on the back, 5-nerved> lanceolate 

 with a short bristle close to the summit, inclosing the caryopsis. 



31. Festuca. Panicle lax or coarctate. Spikelets many-flowered, more 



or less laterally compressed, without a bractea at the base. Glumes 

 unequal, membranaceous, much shorter than the spikelet, usually 

 keeled. Gluraellas lanceolate; outer one rounded on the back 

 very acute or awned at the point, the lateral nerves slightly con- 

 verging and disappearing below the summit. Styles terminal. 



32. BRomus. Panicle lax, spreading, or coarctate. Spikelets many- 



flowered, more or less laterally compressed, without a bractea at 

 the base. Glumes unequal, much shorter than the florets, usually 

 keeled, Glumellas 2, herbaceous ; outer one rounded on the back' 

 2 of the lateral nerves usually uniting and forming an awn below 

 the bifid summit. Styles from below the summit of the caryopsis. 



^ ■ 



r 



J J Florets mixed with long silky hairs. 



34. Phkagmites. Panicle lax, Spikelets distichous, with 3 4 dis- 



tant perfect flowers and a barren 3-androus one at the base, all 

 enveloped with long silky hairs attached to the axis. Glumes 

 membranaceous, rather shorter than the florets, unequal. Glu- 

 mellas membranaceous; lower one tapering with a long narrow 

 subulate point. 



b, Spikelets spiked, either sessile or shortly stalked, and arranged in a simple 



or compound spike or spike-like raceme, 



* Spikelets inserted on different sides of the rachis, sometimes slightly uni^ 



lateral. Spikes usually simple. 



35. Elymus. Spikelets in pairs, each containing 2 — 4 perfect florets. 



Glumes 2, collateral, awnless. Glumellas 2, covering and usually 

 incorporated with the caryopsis. 



36. HoRDEUM. Spikelets ternate, 1—2 usually neuter or barren ; fertile 



ones with one perfect floret and a rudimentary neuter one. Glumes 

 2, collateral, awned. Glumellas 2. 



S7, Triticum, Spike simple. Spikelets solitary, sessile, transverse to 



the rachis, many-flowered. Glumes 2, opposite, nearly equal; 

 outer one with several nerves. 



26. Poa. Spike simple or compound, somewhat unilateral. Spikelets 



approximate, without a pectinated bractea at the base, several- 

 flowered. Glumes 2, opposite; outer one 1-nerved. 



30, Cynosurus. Spikelets approximate, with a pectinate bractea at the 



base, shortly stalked, with 2—5 perfect flowers. Glumes equal, 

 membranaceous, 1-nerved. 



38. Brachypodium. Spike simple. Spikelets solitary, sessile, trans- 



verse to the rachis, remote, at first cylindrical, many-flowered. 

 Glumes 2, opposite, unequal; outer ones with several nerves, 

 much shorter than the contiguous lowermost floret. Inner glu- 

 mella strongly ciliated on the nerves. 



31. Pestuca. Spikelets distant, solitary or in pairs, sessile or nearly 



so, placed edgewise to the rachis, with 6—10 fertile florets, awn- 

 less. Glumes 2, opposite, unequal, much shorter than the lower- 

 most contiguous floret. 



39. LoLiUM, Spike compressed, simple or sometimes slightly compound. 



Spikelets solitary, approximate, sessile, placed edgewise to the 



