Page:The Journal of Indian Botany.djvu/463

DROUGHT RESISTING PLANTS IN THE DECCAN. 41 the supply of water, such as a partially reduced fcaf surface and a thick covering of hairs. The second plant mentioned (Caralluma) had a large number of feeding roots developed and I suspect that it made use of hygroscopic water on the surface of the particles of soil containing much lime on which it grew. Moreover the plant has no leaves and the stems are more or less succulent and possess laticiferous tissue.

Two monocotyledons appear in the main list, and these have of course no tap roots. One is Dipcadi montanum Dalz. the other is A ndro- poqon monticola Schult. The former of these has however a tunicated bulb. It had no leaves at the stage at which it was observed. The plant had just then fruited and was passing into a condition of rest. My colleague Mr. H. P. Paranjapye was able to get me a number of flowering specimens a month later. The latter — Andropogon monticola has fibrous roots like mosb grasses, is perennial and usually remains dormant through the hot weather in the absence of special water supply. It had produced some green leaves in the present instance probably because there had been slight rain, not sufficient however to affect the water content of the soil, a few days before the specimen was collected.

The effect of the extreme drought on the size of the plant and the size and character of the leaves is shown in a number of species, the size of both being generally reduced and the divided charac- ter and hairiness of leaves in a very few of them emphasised (see Nos. 5, 8, 11, 12, 24 and 29). Keduction in the size of the plants is most marked in Polygonum plebejum R. Br., Trianthema pentandra L., Celosia argentea L. and Alyswarpas rugosns var. styracifolius Baker. The reduction of the size of these plants is from one-fifth to one-tenth of the normal, or even further. The increased hairiness of the leaves or leafy organs in a few cases, the pronouncedly branched character of the stem or its well known prostrate or diffuse nature, and the usual prickliness of a large number of plmts are all very characteristic of a dry tract.

The plants in the supplementary list also show similar character- istic peculiarities. The trees and shrubs of course find no difficulty in absorbing moisture from the depths of the soil where their deep descending roots can reach, provided the plants do not happen to grow in very rocky and dry situations. In addition to this great advantage some of them also possess other minor peculiarities which might help them to withstand drought. Thus some of them are leaf- less or shed their leaves to a greater or less extent and reduce the transpiring surface, e.g. Nos. 5, 6, 11, 15, 20, 23, 26, 28, 30, 34. The leaves of some are always much divided and have very small