GRAMINE.E. (grass FAMILY.) 571 
34. Bromus. Lower palea convex or somewhat keeled, awned or 
pointed below the 2-toothed tip or in the cleft. 
* * * Grain free, smooth : lowest flowers of the spikelet imperfect! 
35. Uniola. Spikelets very flat. Flowers strongly compressed and 
keeled, coriaceous, the lowest of a single empty palea. 
(Stamen 1.) 
36. Phragmites. Spikelets strongly silky-bearded on the rachis. 
Flowers membranaceous, the lowest neutral or monandrous. 
Tribe 5. HORDEf NEAS. — Spikelets several- (rarely 1-) flower¬ 
ed, sessile on opposite sides of a zigzag channelled and toothed 
sometimes jointed rachis, forming a solitary spike. Glumes 
horizontal, often side by side in the same plane, sometimes de¬ 
ficient. — Otherwise as in Tribe 4. 
* Spikelets single at each joint of the rachis, several-flowered. 
37. Triticum. Spikelets parallel with the rachis: glumes transverse. 
38. Lolium. Spikelets edgewise on the rachis: glume 1, external. 
* * Spikelets 2-4 at each joint: glumes side by side, or none. 
39. Elymus. Spikelets 2 - 7-flowered ; all fertile. 
40. Hordeum. Spikelets 1-flowered and a stalk-like rudiment, 3 at 
each joint; the lateral commonly imperfect. 
Tribe 6. AVlSNEAS.— Spikelets 2 — several-flowered, panicled, 
the terminal flower mostly imperfect. Glumes and paleae thin 
and membranaceous or chartaceous; the lower palea bearing a 
twisted or bent awn on the back. Stamens 3. Squamulae 2. 
* Lower palea 3-5-nerved, thin or membranaceous. 
41. Aira. Flowers 2: awn below the middle of the rounded back. 
42. Trisetum. Flowers 2-several: lower palea compressed-keeled, 
awned above the middle or near the 2-pointed apex. 
* * Lower palea 7 - many-nerved, firmer in texture. 
43. Danthonia. Awn, or bristle-point, between the 2 teeth of the 
lower palea, composed of 3 confluent nerves. 
44. Avena. Awn from the back, formed of the mid-nerve only. 
II. PHALARlDEiE, Trin. .(not of Kunth.). Spikelets 
3-flowered, the middle flower only perfect; either the tico 
lower or lateral flowers staminate, or neutral and often abor¬ 
tive, or the lower and the terminal one imperfect (in Holcus 
the former usually obsolete). Flowers panicled. 
* Intermediate flower perfect 
45. Arreitatiierum. Lower flower staminate and like the fertile 3- 
androus, awned on the back below the middle; the terminal 
one rudimentary. 
