4 
Third class. 
26. Upper glume covered on the back with numerous hooked 
prickles. Only in Wallis . . Tragus. 613. 
— Upper glume without these prickles . . . 27 
27. Spikelets with numerous awn-like bristles at the base 
Setaria. 618. 
— Spikelets without these bristles .... 28 
28. Glumes with a long awn springing from an incision in the 
point. Polypogon. 629. 
— Glumes awnless or, in Phleum, with a short awn 29 
29. Glumella. single, awn inserted on the back Alopecurus. 623. 
— Glumellas 2 ....... 30 
30. Stigs springing from the top of the spikelet . . 31 
— Stigs springing from the base or side of the spikelet 33 
31. Glumes with a winged keel . . . Phalaris. 620. 
— Glumes with a wingless keel ..... 32 
32. Spikelets with or without a rudimentary upper second fl. 
Stas 3.Phleum. 624. 
— Spikelets with a central hermaphrodite fl, 2 empty lateral 
glumellas, and rudiments of 2 lower fls. Stas 2. 
Anthoxanthum. 622. 
33 (30). Glumellas with hair at the base which is, at least, 
longer than the diameter of the glumella. Glumes com¬ 
pressed-convex .... Calamagrostis. 631. 
— Glumellas without hairs at the base. Glumes much compress¬ 
ed, the base swollen, almost globular Gastridium. 632. 
34 (25). A pectinate bract composed of barren glumellas at 
the side of the spikelet .... Cynosurus. 625. 
— This bract not present ...... 35 
35. Awns 15—30 cm long ..... Stipa. 627. 
— Awns much shorter or 0 ..... 36 
36. Stigs springing from the end of the fl., filiform. Spici- 
form panicle oval or oblong . . . Sesleria. 639. 
— Stigs. springing from the base or side, plumose . 37 
37. Awns springing from above or below the centre of the 
back of the glumella ...... 38 
— Awns 0, or springing from near the top . . 39 
38. Fr. not grooved. Ls flat . . . Triselum. 640. 
— Fr. grooved. Ls setaceous .... Aira. 641. 
39. Spikelets with clavate rudiments (suppressed fls) Melica. 643. 
— Fls all complete . . . . . . 40 
40. Sta 1. Lower glume with a long awn . Vulpia. 654. 
Stas 3. 41 
41. Lower glume with 3, upper with 7 nerves. Stem leafy up to 
the panicle. Only in Wall. . . Sclerochloa. 646. 
— Lower glume with 1, upper with 3 nerves. Stem only leafy 
at the base or up to the middle . . Kceleria. 635. 
42 (24). Spikelets 1-fld. 43 
— Spikelets with 2—many fls . . . • . 52 
