90 INDIAN FOREST MEMOIRS. 



B. — Taxonomy. 



66. Hackel separates the common Mediter- 

 ranean form of this plant as a sub-variety (genuinus) with larger spikelets (0-2 to 0-25 in. 

 long) and with glume IV usually glabrous. 



The Indian plant is referred to sub-variety pur pur as c ens. 



C. — Biological and (Ecological Notes. 



BaMtat. 67. This plant, while undoubtedly requiring 



a liberal supply of available moisture for vigorous development, does not extend into the 

 water-logged soil of the marsh. 



It is thus apparently more sensitive as regards soil aeration than Im,perata, while it 

 requires far more moisture than either S. Munja or S. Narenga. 



It is found on both sandy and clayey loam. Its broad, very thin, dark green leaves are 

 markedly mesophytic, if not indeed hygrophytic in their characteristics, but the plant does 

 not attain the dimensions of the truly hygrophilous species S. arundinaceum. 



Warming 1 states that this species sometimes enters into the composition of reed- 

 swamp in Mediterranean countries, accompanied by Phragmites and Arundo Donaoc. 



The plant is a strong shade-bearer, but its capacity in this respect is often masked by 

 the fact that the roots of neighbouring trees and shrubs frequently cause the available 

 moisture supply to fall below that necessary for its vigorous development. 



In localities where ample water is available by percolation or otherwise, this plant is 

 seen to be a good shade-bearer. 



In this locality it is found at its best on the banks of irrigation channels and water- 

 courses, where ample water is available by percolation and capillarity, but where the soil 

 in contact with its roots is not actually water-logged except for short periods. It usually 

 indicates a soil with the permanent water-table near the surface. 

 Development 68. The remarks given under this head for 



of Culms, . 



season of S. Munja above apply, generally, also to this species. The culms are biennial. The usual 



Activity and period of vegetative activity is from February to November. Flowering takes place in 



ns ' October — November, although panicles are occasionally met with also in December — 



January, thus indicating that activity may in some cases continue practically throughout 



the year. 



During the first season's growth from 1—2 inches of culm is produced with an average 

 of 14 short internodes and carrying 10 green leaves. 



During the second season the long internodes (usually 10) of the flowering culm, carry- 

 ing 10 leaves and terminating in the panicle, are produced. Unlike the Saccharum, how- 

 ever, the leaves of this species are not cut for thatching purposes. 



1 CEcology of Plants, 1909, p. 189. 



[ 80 I 



