86 GBAMINEAE 



shorter than the first lemma; lemmas awnless or with a straight (rarely bent) awn, 

 terminal or from between the teeth of a bidentate apex. 

 Spikelets of two kinds in the same inflorescence, perfect and sterile; spikelets fasciculate in 



1-sided panicles 57. LAMARCKIA. 



Spikelets all alike in the same inflorescence. 



Plants dioecious; perennials with creeping rhizomes or stolons (a few species of Poa are 



dioecious). 

 Spikelets solitary, concealed in the axils of short crowded rigid leaves 



44. MONANTHOCHLOE. 



Spikelets in exserted panicles 54. DISTICHLIS. 



Plants not dioecious. 



Rachilla or lemmas provided with long hairs exceeding the glumes in length ; tall reeds. 



Hairs on lemmas, the raehilla naked 46. ABUNDO. 



Hairs on the rachilla only 47. PHRAGMITES. 



Bachilla and lemmas naked or the hairs shorter than the glumes. 



Spikelets sessile, in short terminal spikes; lemmas 5-toothed; low annual 



45. ORCUTTIA. 



Spikelets in racemes or in open or contracted panicles. 

 Lemmas 3-nerved. 



Lemmas pilose on the nerves, longer than the glumes; callus densely villous. 



48. TRIDENS. 

 Lemmas sometimes pubescent but not pilose on the nerves; callus not villous. 



Glumes equaling or exceeding the spikelet 49. DISSANTHELIUM. 



Glumes shorter than the first floret 50. ERAGROSTIS. 



Lemmas 5 to many-nerved. 



Spikelets nearly sessile in dense 1-sided clusters at the ends of the few panicle 



branches 56. DACTYLIS. 



Spikelets not in dense 1-sided clusters. 



Lemmas flabelliform, many-nerved, petal-like 51. ANTHOCHIXIA. 



Lemmas not flabelliform. 



Palea appendaged on the keels ; inflorescence a simple raceme 



53. PLEUROPOGON. 

 Palea not appendaged. 



Spikelets very broad, much compressed, cordate; lemmas cordate..... 



55. BRIZA. 

 Spikelets not broad and cordate. 



Lemmas keeled, awnless (keeled in some species of Bromus but the 



bifid tip acuminate or awned) 58. POA. 



Lemmas convex or keeled only at summit. 



Glumes large, membranaceous or papery, searious-margined ; upper 

 2 or 3 lemmas empty, convolute around each other.. 52. MELICA. 

 Glumes not scarious-inargined ; upper lemmas not "empty and con- 

 volute around each other. 



Nerves of lemmas 5 to 9, parallel, prominent 59. GLYCERIA. 



Nerves of lemmas not prominent, or not equally so. 



Lemmas obtuse, awnless, scarcely nerved 60. PUCCINELLIA. 



Lemmas acute or awned, or, if obtuse, awned between the teeth 



of the bifid apex. 

 Lemmas entire, acute or awned from the apex (very narrow 



teeth in F. ehneri etc) 61. FESTUCA. 



Lemmas bifid at apex (except B. brizaeformis), the awn if 



present from between the teeth 62. BROMUS. 



Tribe IX. Hordeae. Spikelets 1 to several-flowered (the uppermost floret imperfect), sessile 

 on opposite sides of a flattened or channeled rachis forming a spike; glumes sometime* 

 small or wanting, sometimes placed in pairs in front of the spikelet; auricular appendage* 

 borne at the top of the sheath on each side at base of blade. 



Spikelets solitary at each joint of the raehis (occasionally double in Agropyron). 

 Spikelets placed edgewise to the rachis, the lateral ones with a single glume. 



Spikelets several-flowered 63. LOLIUM. 



Spikelets 1-flowered 64. MONERMA. 



