WATER RELATIONS IN BRYOPHYLLUM CALYCINUM SUBJECTED TO SEVERE DRYING

Abstract

In the whole plant there was some correlation between the age of the tissue examined and the percentage of unfreezable water it contained: the older the tissue the greater the percentage of unfreezable water. As the leaf dries the increase in the c/c of unfreezable water seemed to be the result of the drying rather than being responsible for the remarkable water-retaining ability of the leaf. Plantlets attached to these leaves had the greatest water-retaining ability of any tissue examined, yet there was less correlation between the unfreezable water and the ability to retain water. Some feature other than unfreezable water must be responsible for the ability of the plants and the detached leaves of Bryophyllum to retain their water.