6 4 



SOUTH INDIAN GRASSES 



4. Panicum, L. 



The grasses of this genus are annual or perennial and of various 

 habits. Inflorescence is either a raceme of spikes or, a lax or con- 

 tracted panicle. Spikelets are small, solitary or two to four, rarely 

 more ranked, I- to 2-flowered, ovoid or oblong, rounded, or dorsally 

 or laterally compressed, falling entire with the pedicels. There 

 are four glumes in a spikelet. The first two glumes are empty and 

 the first glume is small (sometimes minute) and fewest nerved. 

 The second glume is equal or very nearly equal to the third glume, 

 oblong-ovate or lanceolate, 5- to many-nerved. The third glume is 

 similar to the second, male or neuter, paleate or not, 3- to Q-nerved. 

 The fourth glume is chartaceous sometimes shortly stalked, ovate- 

 oblong or lanceolate, hardened in the fruit, smooth or rough, 

 bisexual, paleate ; the palea is as long and of the same texture as the 

 glume. Lodicules are cuneate or quadrate and two in number. 

 There are three stamens and an ovary with two style branches 

 ending in feathery stigmas. Grain is free and enclosed by the 

 hardened fourth glume and its palea. 



KEY TO THE SPECIES. 



A. Inflorescence racemose of simple (rarely branched) spikes 

 bearing secund spikelets. 



I. Rachis of spikes broad and flattened. 



(a) Spikelets bi-seriate. 



Spikelets villous ... I. P. Isachne. 



Spikelets glabrous. 



Spikes shorter than the internocles. 2. P. flavidum. 

 Spikes longer than the internodes. 3. P. fluitans. 



(b) Spikelets 3- to 5-seriate. 



Third glume awned. 

 Stems stout, erect 

 Stems stout, prostrate at base 



Third glume cuspidate. 

 Stems slender 



II. Rachis of spikes narrow, filiform, terete or angular. 



First glume shorter than the third. 



First glume semilunate, about ] i of the 



third glume ••• 7- 



First glume Y 2 of or less than Y 2 of 

 third glume, 5-nervecl ... ■•• 8. 

 Leaf base broad or cordate. 

 Fourth glume shortly awned ••• Q. 

 Fourth glume muticous 10. 



B. Inflorescence a contracted or open panicle. 



I. Panicle contracted and spike-like. 



Spikelets lanceolate and first glume 

 minute 



II. Panicle effuse. 



Annuals ; first glume nearly Y\ of 



the third glume 

 Perennials ; first glume less than 



% of the third glume 13. P. repens. 



4 P. Crus-galli. 



5. P. stagninum. 



6. P. colonum. 



P. prostratum. 



P. ramosum. 



P. javanicum. 

 P. distachyum. 



II. P. interruptum. 



12. P. trypheron. 



