3 o2 GRAMINEAE 



4. Tristegineae (paleae membranous ; glumes herbaceous or 



firm and papery, the lowest smaller or narrower than the 

 rest; spikelets falling singly from the twigs of a panicle) : 

 Arundinella. 



5. Paniceae (paleae usu. cartilaginous, leathery or papery ; 



glumes more delicate, usu. herbaceous, the lowest usu. 

 smaller ; spikelets falling singly from the twigs of a panicle 

 or unjointed spike-axis) : Paspalum, Panicum, Setaria, 

 Cenchrus, Pennisetum, Spinifex. 

 b. Hilum linear ; spikelets lat. compressed. 



6. Oryzeae: Zizania, Oryza, Lygeum, Leersia. 



B. Spikelets i many-flowered; when i -flowered often with a pro- 

 longation of the axis above the fl., their stalks usu. jointed 

 above the glumes, so that they fall off leaving these on the 

 axis ; when i- or more-flowered, always with distinct inter- 

 nodes between the fls. 



a. Stem herbaceous annual. No petiole, or joint between 

 blade and sheath. 



7. Phalarideae (spikelets in panicles, spikelike panicles or 



racemes on distinct stalks sometimes very short, not set 

 in notches on the main axis; i -flowered, with 4 glumes 

 and i -nerved sup. palea): Phalaris, Anthoxanthum. 



8. Agrostideae (as 7, but spikelets with two or no glumes and 



2-nerved sup. palea) : Aristida, Stipa. Phleum, Alopecurus, 

 Sporobolus, Polypogon, Agrostis, Calamagrostis, Ammo- 

 phila, Apera, Lagurus. 



9. Aveneae (infl. as 7, but spikelets 2- many-flowered ; inf. 



paleae usu. shorter than glumes, with twisted awn upon 

 the dorsal side, more rarely with no awn or with an awn 

 upon the tip as 10, but then always with 2 almost opp. 

 fls. and no prolongation of the axis beyond them) : Holcus, 

 Aira, Corynephorus, Deschampsia, Trisetum, Avena, 

 Arrhenatherum, Danthonia. 



10. Festuceae (as 9, but int. palea usu. longer than glume, without 



awn or with untwisted awn at tip) : Sesleiia, Gynerium, 

 Arundo, Phiagmites, Eragrostis, Catabrosa, Melica, Briza, 

 Dactylis, Cynosurus, Poa, Glyceria, Festuca, Bromus, 

 Brachypodium. 



11. Chlorideae (spikelets in 2 rows approximated to one 



another, forming a one-sided spike or raceme with un- 

 jointed axis) : Cynodon, Spartina, Chloris, Bouteloua, 

 Eleusine. 



12. Hordeeae (spikelets in 2, or rarely more, opp. rows, forming 



a symmetrical, rarely one-sided, spike) : Nardus, Lolium, 

 Agropyrum, Secale, Triticum, Hordeum, Elymus. 

 b. Stem woody, at least below ; leaf often petiolate, finally 

 separating from its sheath by a joint. 



13. Bambuseae: Arundinaria, Bambusa, Dendrocalamus. 

 Space will not permit of giving a key to the genera; the student 



should work through the commoner ones with a flora, or with Ward 

 or Hutchinson's British Grasses. 



