45 



21. Axis and branches of panicle scabrid, without tubercular 



glands. Glumes smooth P. hirsuta. 



Axis and branches of panicle with tubercular glands. 

 Keels of glumes scaberulous P. rupestris. 



22. Annual 23 



Perennial 25 



23. Spikelets IJ-IJ lin. long. Anthers |-i lin. long ... 



P. airoides- 



Spikelets 2-2J hn. long. Anthers 1 lin. long 24 



24. Panicle lax, divaricate. Blades filiform or involute ... 



P. patula. 

 Panicle more or less contracted. Blades flat. P. euadenia. 



25. Spikelets 3-4 lin. long *. 26 



Spikelets scarcely 2J lin. long ... 28 



26. Blades closely and prominently striate, curling at length. 



Margins fringed with numerous tubercles. P. aspera. 



Blades slightly striate not curling. Margins not or 



scantily tubercled 27 



27. Culms densely and distichously leafy at the base. Ligular 



fringe inconspicuous. Sheaths scantily bearded or 



beardless P. subulifolia. 



Lower leaves fewer or more distant. Ligular fringe 

 conspicuous. Sheaths bearded P. leucopogon. 



28. Spikelets 2^-4 lin. long. Blades firm, filiform or 



setaceous 29 



Spikelets 1-2^ lin. long. Blades soft or flaccid or if 

 somewhat rigid, then very fine or very short ... 33 



29. Side bristles 3-4 on each side of the valve ... P. heptamera. 

 Side bristles 1 on each side of the valve 30 



30. Spikelets 3|-4 lin. long. Blades setaceous, glabrous 1-4 



in. long P. burchellij. 



Spikelets 2^-3 lin. long 31 



31. Lower valve with 3 bristles. Upper with a long kneed 



awn and 2 bristles .P. heterochaeta. 



Both valves alike 32 



32. Blades very hairy 1-1| in. long.^ Glumes, pubescent. 



P. tomentella. 



Blades glabrous or scantily hairy. 2-8 ins. long. Glumes 



glabrous P. angustltolia. 



33. Panicle very lax, open (at least temporarily) 34 



Panicle contracted, usually dense (rarely open in 



P. thunbergii) ". 37 



34. Valves with the lobes gradually passing into bristles. 



Blades small, hairy P. jugorum. 



Valves with the lobes distinct from the bristles 35 



