910 CXLVII. GEAMIXE.i:. 



Lower invol.-glume not furnished with 

 oil-glands; spikelets awned. 

 Spikelets iu alternate pairs or lower 

 solitary. 

 Inflorescence usually elongate ; sessile 



spikelets many e31. Andropogon. 



Inflorescence very short ; sessile 



spikelets 2 32. PsEUDANTIIISTIBfA. 



Spikelets diuiorpiiio, the 4 lower sessile 



forming an involucre round the upper. 



Rhachis articulate above the invo- 



lu oral spikelets 33. Tiiemeda. 



Rbachis articulate below the invo- 

 lucral spikelets 34. Iseilema. 



Tribe 3. MA.YIi'ESl. Inflorescence moncecious, spicate, the male 

 and female spikelets on the same spike (in which case the females 

 are at the base of the spike) or on different spikes ; spikelets never 

 awned, the male and female very dissimilar. 



Fruiting spikelet enclosed in a stony polished nut-like 



bract 35. Ooix. 



Fruiting spikelet with the lower invol.-glume forming a 

 crustaceous nut-like envelope to the other glumes and 

 grain 36. Polytoca. 



SERIES II. Mature spikelets breaking up, leaving the persistent 

 or subpersistent glumes on the pedicel, or if falling entire, then not 

 consisting of 2 heteromorphous florets as in Series I. 



A. Leaf-blades rarely (Centotheca) transvevsehj veined, not articulate 

 on the sheath. 



Tkibe 4. ARUNDINELLE^. Florets 2, heteromorphous, , the 

 lower awnless, male or neuter. Ehachilla not produced beyond 

 the upper floret. Lower floral glume awnless, rather resembling 

 the invol.-glumes ; upper generally awned ; awn from the sinus 

 often between 2 bristle-like lateral awns (rarely from the entire obtuse 

 tip), usually geniculate and twisted below the knee. 



Spikelets solitary on distinct pedicels, small ; flaps of the 



palea auricled 37. Arundinella. 



Spikelets in clusters of 3, large; flaps of the palea not 

 auricled 38. Tkistachya. 



TiUBE 5. ARUNDINE.aE. Florets 2-many, enveloped in very long 

 hairs springing either from the callus or from the back or margin of 

 the floral glumes. Glumes membranous, often hyaline. 



Hairs springing from the margins of the upper floral 



glmue 39. Tiivsanol.kna. 



Hairs springing from the callus 40. Piiragmites. 



Tribe G. STIPE.ffi. Floret 1. Ehachilla not produced beyond the 

 upper floral glume wliich is 2-sexual, hardened when mature, tiglitly 

 enveloping tiie fruit ; nerves joining or closely approaching at the 

 tip. Awn terminal (rarely 0). 



Awns 3 from the entire tip or 1 simple below, 3-branched 



above, rarely quite simple 41. Aristida. 



TniBE 7. AGROSTEiE. Floret 1. Rhachilla rarely produced 

 bivond the floret. L pper floral glume membranous, not changed 



