Page:The Journal of Indian Botany.djvu/451

DEOUGHT EESISTING PLANTS IN THE DECCAN. 29 estimate. To get as close as possible to an idea of the actually available water for the plants, the soil was dried at 45 to 50 c. on a sand bath till the weight was constant.

The survey, as already stated, was made in May 1919. It must be pointed out, however, that before the observations and notes were completed, there had been slight rain in a few places. But this rain rarely amounted to more than a few hundredths of an inch.

The principal plants found living and growing under the condi- tions of extreme drought described are shown in the following list : —

1. Polygonum plebejum B. Br. — This was found on medium black sticky soil at Talegaon * on May 1, 1919. The available moisture round the roots was about 3,00 per cent.

An examination of the herbarium material of the species shows that under different rainfall or soil conditions the species varies a great deal as regards the size of the plant, the length of the internodes, and the size of the leaves.

As collected now it was a very small prostrate or diffuse plant scarcely half an inch above the ground, branched from near the base, branches barely reaching an inch in length. The root was slender, Xa inch in diameter, and 3 — 4 inches in length. It had no lateral bran- ches. The leaves were very minute, scarcely i inch in diameter. The plant was in flower and showed some purple anthocyanin pigment.

Beduction of the size of the plant and of the leaves to about i-i of the well developed size is therefore the only response of the plant in the present abnormal conditions.

2. Chrozophora prostrata Dalz. — Bather common. This was found on medium black, sticky soil at Talegaon, on May 1, 1919. The available moisture round the roots was about 3'00 per cent.

This plant also seems to vary much in different places, as regards the length of the branches and the size of leaves.

As collected now it was a small prostrate plant, scarcoly an inch above the ground. The root was slender, ro inch in diameter and 5 — -6 inches in length, devoid of lateral branches. Branches of the stem were 1 — 2 inches long, and leaves stellately hairy. The leaves were ir — j inch long and broad. The plant was in fruit. It had also developed some anthocyanin pigment in the stem and leaves.

Thus reduction in size is apparently the only response of the plant in the present conditions.

3, Solatium xanthocarpum Schl. — Bather common. It was found on medium black soil which was somewhat more sticky


 * The rainfall of Talegaon is closely similar to that shown above for Vadgaon.