228 Graminece. {Andropogon* 



palea small or o; lodicules 2, cuneate; stam. 3-1 ; stigmas 



laterally exserted; pedicelled spikelets usually smaller than 



the sessile; grain various. — Sp. about 200; 78 in Fl.B.Ind. 



The heterogeneous collection of grasses brought together by Hackel 

 under Andropogon have been classified by that able systematist under 

 11 subgenera, of which 8 are Sinhalese, and are indicated below. Of 

 these, Sorghum, Chrysopogon, Heteropogon, and Cymbopogon are con- 

 sidered to be genera by various earlier authors, and may, in Dr. Stapf's 

 and my opinion, be eventually adopted as such. In this work I have 

 arranged the Sinhalese subgenera somewhat differently from Hackel (as 

 adopted in the Flora of B. India), taking the cupulac character versus the 

 truncate of the articulations of the internodes of the spike as a fairly 

 constant primary character. 



Key to the Subgenera of Andropogon. 

 Internodes of spike truncate at the top, not cupped. 

 Isozygi. Sessile spikelets all similar. 

 Spikes of many spikelets. 



Internodes of spikes flattened with a dia- 

 phanous centre and thickened margins 1. Amphilophis. 

 Internodes of spikes terete or angular with 

 no diaphanous centre. Sessile spikelets 

 dorsally compressed . . . .2. SORGHUM. 

 Internodes of spikes laterally compressed . 3. Vetiveria. 



Spikes of 3 spikelets 4. CHRYSOPOGON". 



Heterozygi. Lower sessile spikelets of the spike 

 dissimilar from the upper sessile, mostly 

 neuter. 

 Spikes 2 or more, digitate or panicled . . 5. DlCHANTHIUM. 



Spikes solitary 6. HETEROPOGON. 



Internodes of spikes deeply cupped at the top. (See 

 also A. polyptichus.) 

 Spikes solitary, no spathaceous bracts . . 7. SCHIZACHYRIUM. 



Spikes binate, each pair with a spathaceous bract 8. Cymbopogon. 



Key to the Species of Andropogon. 

 Subgen. 1. Amphilophis. 



Spikes digitate or fasicled, not panicled. 



Spikes 4-6 in., glume I not pitted . . 1. A. Pseudischjemum. 

 Spikes 1-2 in., glume I pitted . . . 2. A. pertusus. 



Spikes panicled 3. A. intermedius. 



Subgen. 2. Sorghum. 



Spikelets silky with usually pale hairs . . 4. A. HALEPENSIS. 

 Spikelets villous with purple hairs . . 5. A. SERRATUS. 

 Subgen. 3. Vitiveria. 



Glume I with muricate sides . . . 6. A. SQUARROSUS. 



Glume I smooth 7. A. VENUSTUS. 



Subgen. 4. Chrysopog-on. 



Pedicel of upper spikelet \ or more longer 

 than the sessile spikelets. 

 Pedicel of upper spikelet glabrous . . 8. A. ACICULATUS. 

 Pedicel of upper spikelet villous . . 9. A. ZEYLANICUS. 

 Pedicel of upper spikelet not \ as long as the 



sessile spikelet 10. A. monticola. 



