THE ECOLOGY OF THE UPPER GANGETIC PLAIN. 315 



Dry meadow stage. The wet meadow merges gradually into 

 what may be called dry meadow (Fig. 11), a very extensive and 

 uniform association dominated by perennial grasses. Under natural 

 conditions it probably would be but an inconspicuous incident in the 

 topographic succession, but due to the retrogressive influence of the 

 very intense human factors, it has become for the time being the 

 climatic climax over most of the area, This stage is connected with 

 the wet meadow by Cynodon dactylon and Eragrostis tenella. The 

 latter is a short-lived annual that flourishes everywhere during the 

 rainy season, and almost completely disappears by the middle of 

 winter. 



The typical dry meadow (Fig. 11) is dominated by two perennial 

 grasses, Andropogon intermedins Br., and Elusine aegyptica: Desf. 

 Both are able to produce a luxurient grass cover, but under severe 

 grazing they assume a dense compact tufted habit ; both propagate 

 freely by runners. Under excessive grazing the Andropogon is the 

 more persistent. In slight depressions and in the shade of trees, 

 where growth conditions are a little less severe, three perennial 

 Leguminosae, Desmodium triflorum DC, Indigo/era enneaphylla L., 

 and Alysicarpus monilifer DC. are very charateristic components of 

 the dry meadow. They too have the tufted prostrate habit of growth. 

 All are excellent pasture plants, and owe much of their value to their 

 persistence under grazing and drought. 



During the rainy season there is a conspicuous development of 

 Eragrostis tenella, and of two annual Leguminosae, Cassia obtiisifolia 

 L. and Grotalaria medicagitiea Lamk. The last two are often so 

 abundant as to give character to the dry meadow vegetation, but 

 they die at the beginning of the cold season, and little trace of them 

 remains in the hot season. 



Overgrazing and the intense aridity of the hot season greatly 

 reduce the Iuxurience of the grasses of the dry meadow (Fig. 11), and 

 another important constituent then becomes prominent- This is a 

 series of small xerophytic and very persistent perennials that are able 

 to survive both the grazing and aridity because of the development 

 of effective perennating organs. All have deep tap roots with a 

 perennial crown of stem, and most of them have a well developed 

 rosette habit of growth. As the cold season advances and gradually 

 merges into the hot season, the older and larger leaves fall, the more 

 delicate stems are grazed off or die, and the aerial parts become re- 

 duced to a small compact crown of very resistent vegetation. In this 

 condition they are able to bloom and produce seed abundantly. Some 

 of the more common of these plants are : — Convolvulus pluricaulis 

 Chois., LepidagatJiis trinervis'.Nees, Justicia simplex D. Don, Eu- 



