138 SOUTH INDIAN GRASSES 



CHAPTER VIII 



TRIBE IV— ANDROPOGONE^;. 



Andropogoneee is a very large tribe with about thirty genera. 

 It is very well represented in South India and some genera are of 

 very wide distribution. 



The spikelets are usually arranged in pairs at each joint, one 

 sessile and the other stalked. The spikelets may all be similar as 

 in Imperata or they may be different as in Isachaemum and 

 Andropogon. There may be only one flower in the spikelet as in 

 Eremochloa and Saccharum or two as in Ischaemum and Apocopis. 

 In the genera Polytoca and Coix the spikelets are unisexual and 

 the male and female spikelets are found in the same inflorescence, 

 the female being below and the male being continuous with it. 

 The spikelet nearly always consists of four glumes, the first or the 

 first and the second being firmer and coriaceous or chartaceous. 

 The flowering glumes are always shorter than the empty glumes, 

 and are hyaline. The fourth glume is often awned or reduced to 

 an awn. 



The main rachis of the inflorescence is usually jointed at the 

 base. In addition to this the rachis may be jointed all along its 

 length, so as to become separated into distinct joints when mature 

 as in Rottboellia, Saccharum and Andropogon, or it may be 

 continuous as in Imperata. The pedicels of spikelets and the 

 lower portions of the rachilla of the spikelets may have long hairs. 



Sub. Tribe I. MaydeaB. 



The spikelets are all unisexual, spicate, the male and female 

 spikelets are dissimilar, and are on the same or on different 

 spikes. 



Fruiting spikelets enclosed in a stony nut- 

 like polished bract ... ... 16. Coix. 



Fruiting spikelets with the first glume 

 forming a crustaceous nut-like envelope 

 to other glumes and grain ... 17- Polytoca. 



Sub. Tribe 2. Saccharea*. 



The spikelets are all similar, in compound racemes or panicles ; 

 the first glume not sunk in the hollow of the rachis. Spikelets are 

 i-fiowered. 



Rachis not fragile ; spikelets in cylindrica 



silvery thyrsus 18. Imperata. 



Rachis fragile ; spikelets in open very much 

 branched silky panicles ... 19. Saccharum. 



Sub. Tribe 3. Ischemeaz. 



Spikelets many, dissimilar, in solitary, digitate or fascicled 

 racemes or spikes ; first glume not sunk in the hollow of the rachis. 



