Ecology of Indian Desert. IX. An Investigation on the Behaviour of Leaf and Stomata in Capparis decidua (Forsk.) Edgew.

Abstract

Capparis decidua (F orsk .) E dgew . is a dominant species on gravel and compact sandy soil and makes scattered groups of bushes on the sand dunes of Indian arid zone as well. It belongs to the “leafless” category of xerophytes and displays an unique example of leaflessness by producing minute, short-lived leaves with a maximum life tenure of 30—45 d during such a period of the year when available soil moisture is at its minimum. Investigations were made in relation to leaf persistence, distribution of stomata, stomatal opening and water loss, water content and Crassulacean Acid Metabolism (CAM), and neutral red uptake pattern in isolated epidermal peelings. It has been observed that the leaves are produced by new branches only. Stomata are peculiar in having more width than length and being sunken in branches only. Intensity of water loss was directly related with the degree of stomatal opening; being maximum in the evening followed by morning, and minimum in the noon which also coincides with the water contents of leafy branch and old leafless branch. CAM was also observed in this species although Titrable Acid Number (TAN) was very low. Neutral red uptake pattern revealed that the larger opening of the foliar stomata and as a consequence prompt uptake of this vital dye with visible protoplasmic streaming in guard cells is an indication of their higher metabolic activity.