98. GRAMINE^E. 479 



23. POLYPOGON. Pan. close, spikelike. GL scarious, each 

 with a long bristle from just below the notched tip. Fl. 1. 

 Lower pale usually awned from just below the tip. 



24. GASTRIDIUM. Pan. close, spikelike. Gl. membranous, 

 acute, awnless, ventricose at the base, much exceeding the 

 flower. Fl. 1. Lower pale truncate or toothed at the end, 

 with or without a dorsal awn. 



Tr. X. AVENEJE. Spikelets with 2 or more flowers ; upper 

 often barren. GL equalling or overtopping the flowers. 

 Lower pale awned. Style short or 0. 



25. HOLCUS. Fl. 2 ; lower perfect, awnless (or very rarely 

 awned) ; upper usually male, with a dorsal awn. Pales 

 hardening on the fruit; tip of lower entire. 



26. WEINGAERTNERTA. Fl. 2, perfect, awned. Awn straight, 

 jointed in the middle ; the upper portion clavate j a tuft of 

 hairs at the joining. Tip ot lower pale entire. 



27. AIRA. Pan. lax. Fl 2, with or without the rudiment 

 of a third (sometimes perfected). Lower pale denticulate 

 or bifid at the tip, terete on the back. Awn dorsal, kneed, 

 (in A. ccespitosa straight). Ovary glabrous. Fr. not crested. 



28. TRISETUM. Spikelets crowded. Fl. 2 6. Lower pale 

 with faint lateral veins, ending in 2 acute teeth, awned. 

 Awn dorsal, kneed and twisted. Ovary glabrous. Fr. 

 neither crested nor furrowed. 



29. AVENA. Fl. 2 or more. Lower pale with lateral veins, 

 awned, ending in 2 points. Awn doreal, kneed and twisted. 

 Ovary hairy at the- top. Fr. crested and furrowed. 



30. ARRHENATHERTJM. pi. 2, with a rudiment ; lower fl. 

 male with a long kneed and twisted awn from below its 

 middle ; upper with a short straight awn from near the 

 tip. Pales herbaceous, ending in 2 points. Ovary hairy 

 at the top. Fr. oblong, terete, downy, not furrowed. 



Tr. XL FESTUCE^E. Spikelets with 2 or more flowers, 

 upper often barren. GL falling short of the lowest Jlower. 

 Style short or 0. 



f Lower pale ^vith nearly par ailed veins which do not join to form 



an awn. Awn 0. Styles terminal. 



! Lower pale 2 3-fid. 



31. SIEGLINGIA. Fl. 2 4. Lower pale rather coriaceous, 

 rounded on the back, bifid with an intermediate broad 

 point. Nut free. 



