40 



GRAMINEAE (GRASS FAMILY) 



Tribe III. PANICEAE 



Spikelets without a subtending involucre of bristles or valves. 

 Spikelets in one-sided racemes or spikes. 



First glume well developed ...... 



First glume small or abortive. 



Plant annual . . 



Plant perennial ........ 



Spikelets not in one-sided racemes or spikes. 



Glumes awned . . . . . ... 



Glumes not awned ........ 



Spikelets involucrate. 



The involucre consisting of bristles . 



The involucre consisting of spine-bearing valves forming a bur 



6. Paspalum. 



7. Syntherisma. 



8. Brachiaria. 



Tribe IV. ORYZEAE 



Flowers perfect; glumes wanting 



Tribe V. PHALARIDEAE 



Uppermost floret perfect, the others empty ..... 

 Uppermost floret perfect, the others staminate .... 



Tribe VI. AGROSTIDEAE 



Lemma with a long terminal awn, and closely embracing the grain. 

 Spikelets not in pairs. 



Fruiting lemma thin and membranous 

 Fruiting lemma firm and indurated. 



Awns 3-b ranched . . . 



Awns simple. 



Twisted, persistent on the lemma 



Straight, deciduous from the lemma. 



Lemma glabrous or appressed-pubescent 



Lemma long silky-pubescent . . . . 



Spikelets paired, in a spike-like raceme ..... 



Lemma awnless or short- awned, and loosely investing the grain. 

 Inflorescence a dense spike. 



Spikelets persistent; lemma awnless or with a short terminal awn. 

 Spikes cylindrical ........ 



Spikes ovoid ......... 



Spikelets early deciduous; lemma with a dorsal awn 

 Inflorescence a loose panicle. 



Pericarp discharging the seed at maturity. 



A diminutive alpine perennial ...... 



Larger and mostly at middle and lower altitudes. 

 Nerves of lemma not pilose . . . . . 



Nerves of lemma pilose ....... 



Pericarp permanently investing the seed. 



Palet 1 -nerved; stamen 1 



Palet 2-nerved; stamens 3. 

 Lemma naked at the base 

 Lemma with a tuft of long hairs at the base. 

 Thin-membranous . . ... 



Chartaceous . 



9. Echinochloa. 



10. Panicum. 



11. Chaetochloa. 



12. Cenchrus. 



13. Homalocenchrus. 



14. Phalaris. 



15. Hierochloe. 



20. Muhlenbergia. 



16. Aristida. 



17. Stipa. 



18. Oryzopsis. 



19. Eriocoma. 

 21. Lycurus. 



22. Phleum. 

 27. Polypogoii. 



23. Alopecurus. 



24. Phippsia. 



25. Sporobolus. 



26. Blepharineuron, 



28. Cinna. 



29. Agrostis. 



30. Calamagrostis. 



31. Calamovilfa. 



Tribe VII. AVENEAE 

 Awn of the lemma dorsal. 



Spikelets less than 1 cm. long. 



Lemma erose-truncate 



Lemma 2-toothed, with awn twisted and bent . 

 Spikelets more than 1 cm. long . 

 . \\vii of the lemma terminal, between the teeth 



32. Deschampsia. 



33. Trisetum. 



35. Avena. 



36. Danthonia. 



