ABSORPTION OF ATMOSPHERIC WATER BY LEAVES AND STEMS OF A CHAEMEPHYTE IN PRE-SAHARAN TUNISIA - ANTHYLLIS HENONIANA (FABACEAE)

Measurements of predawn water potential made in the presaharian Tunisi a (Medenine) on A. henoniana suggest that this species is able to abso rb directly atmospheric water through its leaves and (or) stems. Measu rements of water potential were also made on several plants in control led conditions. Cross sections of stems of various ages and of leaves were examined. There was a good correlation between the thickness of t he cortical parenchymatous tissue in leaves and young stems and the ab ility of a plant to maintain a less negative water potential in condit ions of high atmospheric humidity. The water is apparently taken up by the vascular system. This ability would allow A. henoniana to benefit from the many dew days observed in its area of distribution and would improve its water balance.