( 50 ) 



usar tracts in Northern India, often constituting the entire vegetation. 

 As such it is not only useful as an unmistakeable indicator of reh-infected 

 soils, but also by affording an abundant supply of fodder over large areas 

 of land where other plants are unable to exist. The experiments now 

 being undertaken at Aligarh and Cawnpore for the reclamation of reh- 

 infected land are of great interest in regard to the changes affecting the 

 growth of this grass. The immediate effect of excluding all cattle from 

 usar land is the production of a more luxuriant growth of the usar grass, 

 and its rapid extension over what were formerly bare efflorescent patches. 

 At the same time other kinds ot grasses quickly take advantage of the 

 improved condition of the soil consequent on the more vigorous growth 

 of the usar grass ; for the thicker coating of usar grass helps to moderate 

 the scorching rays of the sun, and in this way diminishes the upward 

 capillary movement of the reh salts. On all usar tracts there are usually 

 to be seen patches of various sizes scattered here and there, usually in 

 the form of ridges or mounds. These raised portions are nearly always 

 found to support an assortment of plants indicating a distinctly differ- 

 ent condition of soil compared to that of their surroundings. Dub and 

 other valuable grasses form a large proportion of the vegetation of these 

 raised patches, and are ever ready to encroach wherever the ground m 

 their immediate neighbourhood becomes fitted for their existence. The 

 usar grass does not appear to be able to hold its own on ground which is 

 capable of supporting these other grasses ; it will, therefore, gradually 

 disappear as the reclamation of the reh-infected tracts proceeds. 



S. pallidus, Nees. Syn.— Vilfa pallida, Nees. Vern.— Punjab : 

 Budhan and budhar (E. Punjab), palinji (Hissar) ; N.-W. Pkov. : Karno 

 (Royle). 



Similar in height and habit to S. orientalis, but the stoloniferous 

 rhizomes are much shorter; the panicles are narrower, their branches 

 shorter and more erect. 



Common in the Punjab and Rajputana on sandy ground, growing gre- 

 gariously, and affording a considerable amount of forage. 



50. POLYPOGON, Desf. Species about 10, inhabiting temperate regions 

 of the world. Panicle densely spikelike. The long weak awns which give it a 

 soft and brush-like appearance arise from the outer empty glumes, the flowering 

 glumes have very short awns. 



P. monspeliensis, Desf.* Syn. — Alojpecurus monspeliensis, Linn. ; A.pani- 

 ceus y Linn, j Phleum crinitum, Schreb. ; Agrostis jpanicea, Willd. Vern. — Pun- 

 jab : Malliar (Salt Range), mandusi (Karnal). Rajput ANA : Chitra (Ajmere). 



Stems about one foot high. Awn of empty glumes three or four times as long as 

 the glume. 



• See Plate E., Fig. 25, of present Volume. 



