I'd seen them before, but yesterday morning I looked closely at the tiny beads of water forming on the edge of the leaves. I found these on my Balsam, Cyanotis cristata and a purple Tradescantia. Pictures from the first two attached. Earlier I had thought it was the dew but these beads are not on other plants. We have had heavy rains during May which is a summer month with temps touching 37C here with minimum of 21-22C. The air is humid. Due to the rains it was a comparatively cool May, though humid. Someone told me that plants holding more water can exude excess of moisture like this. Is this true and can anyone explain the exact phenomenon?