115 



28. Empty glumes obtuse, much shorter than the obtuse or im- 

 perfectly 3-toothed flowering glumes 106. Catabrosa 



28. Empty glumes acute, nearly equaling or as long as the acute, 



or very short-awned flowering glumes 105. Kceleeia 



29. Spikelets nearly sessile in dense one-sided clusters at the ends 



of the few panicle branches; flowering glumes strongly com- 

 pressed-keeled, the keel extending into a short point or 

 awn 114. Dactylis 



29. Spikelets not in dense one-sided clusters at the ends of the 



panicle branches 30 



30. Keels of the palea with a distinct crest or wing-like append- 



age; flowering glume 7-nerved, the mid-nerve slightly pro- 

 longed beyond the entire or emarginate apex; inflorescence 

 a simple raceme 110. Pleuropogon 



30. Keels of the palea not winged 31 



31. Spikelets somewhat heart-shaped; flowering glumes cordate 



at the base, many-nerved, strongly rounded on the back, 

 becoming ventricose. (Bromus brizseformis may be looked 

 for here) 113. Briza 



31. Spikelets not heart-shaped; flowering glumes not cordate at 



base '. 32 



32. Flowering glumes very broad, fan-shaped (flabelliform) , thin- 



membranaceous, obscurely few- to many-nerved; spikelets 

 crowded in short, spike-like panicles 108. Anthochloa 



32. Flowering glumes not broad fan-shaped 33 



33. Callus barbate or pilose. (Some species of Poa may be looked 



for here) 34 



33. Callus naked 38 



34. Rachilla and callus both pilose-hairy, hairs 1-2 mm. long; 



second glume acute, nearly as long as the spikelet; flowering 

 glume, with a very short awn just below the bidentate apex 

 or awnless 121 . Graphephorum 



34. Rachilla and callus naked or nearly so 35 



35. Nerves of the flowering glumes 5-9, manifest 36 



35. Nerves of the flowering glumes 3-5, indistinct or obsolete. . 37 



36. A low, slender grass with strict, few-flowered panicles, 2-4 cm. 



long; flowering glumes pilose on the margins, smooth and 

 rounded on the back, subcoriaceous, tridentate at the rather 



broad apex 98. Sieglingia 



36. A tall, stout grass 9-15 dm. high, with ample, open panicles 

 16-30 cm. long; flowering glumes glabrous on the margins, 

 apex erose-dentate 120. Scolochloa 



