dO GMAMLXEAE (gRASS FAMILY) 



Tribe VIII. 'SHLORIDEAE. Spikelets 1-several-flowered, in 1-sided spikes which are digital* oi 



jianiculate, sometimes solitary. 



* Spikelets all alike. 



■•- Spikelets strictly 1-flowered, no sterile lemma. 



■M- Rhachilla articulated below the glumes. 



4S. Spartina. Gl-inies narrow, unequal. 



49. Beckmannia. Glumes broad, boat-shaped, inflated, equal. 



++ ++ Rhachilla articulated above the glumes. 

 5(>. Cynodon. Spikes digitate ; plants extensively creeping. 



51. Schedonnardus. Spikes paniculate ; plants cae.spitose. 



-i- -i- Spikelets with more than 1 floret. 

 ++ Perfect floret 1, additional florets staminate, neuter or rudimentary. 



= Lowest floret perfect. 



52. Gymnopogon. Spikelets remote, appressed. 



53. Chloris. Sjiikelets imbricated; fertile lemma 1-awned or awnless; spikes more or less 



whoried or digitate. 



54. Bouteloua. Spikelets imbricated ; fertile lemma 3-awned ; spikes racemose. 



= -= Lowest florets neuter, third perfect. 



55. Ctenium. Spike solitary ; second glume bearing a stout divergent dorsal awn. 



++ ++ Perfect florets 2 or more. 

 = Spikes few, stout, digitate. 



56. Dactyloctenium. Rhachis of spike prolonged beyond the spikelets ; second glume and at 



least lowest lemma cuspidate. 



57. Eleusine. Rhachis of spike not prolonged beyond the spikelets, neither glumes nor lemmas 



cuspidate* 



= = Spikes numerous, Terj' slender, racemose. 



58. Leptochloa. Spikelets not crowded, often slightly pediceled. 



* * Spikelets unisexual, dissimilar ; plants dioecious or monoecious. 



59. Buchloe. Staminate spikes exserted, racemose ; pistillate spikelets nearly capitate, partially 



included in broad sheaths. 



Tribe IX. FESTUCEAE. Spikelets 2-many-flowered, usually perfect, pedicellate in racemes or in 

 loose or dense panicles; glumes shorter than the lowest floret; lemmas l-several-nerved, awn- 

 less or with 1-several straight awns, terminal or borne just below the apex. 



* Rhachilla clothed with long silk}' hairs, exceeding the florets. 



60. Phragmites. Lowest floret staminate, the others perfect. 



* * Rhachilla naked or with hairs much shorter than the florets. 

 +- Callus and nerves of lemma densely bearded (not cobwebby). 



61. Tridens. The three nerves or only the middle one excurrent between the acute lobes of the 



lemma ; palea not ciliate-fringed. 



62. Triplasis. Midnerve excurrent between the truncate lobes of the lemma; palea conspicu- 



ou.sly ciliate-fringed ; florets remote. 



■•- -t- Callus and nerves glabrous or cobwebby, or callus sparsely bearded. 



++ Lemma coriaceous, smooth and shining, without a scarious margin. 



■= Spikelets dioecious. 



68. Distichlis. Spikelets large, compressed, in a small crowded panicle. 



= -= Spikelets perfect. 



67. Uniola. Lower 1-4 lemmas empty. 

 66. Diarrhena. ri>per 2-4 lemmas empty. 



■•-•■ +*■ Loininas membranaceous, or if subcoriaceous having a scarious margin. 



«= Lemmas 3-nerved. {Koeleria might be looked for here, but the upper glume about equals 



the lower floret.) 



83. Eragrostis. Spikelets 3-many-flowered. 



