Do Plants "Perspire"?
On a hot summer morning you may often see dew shining on leaves. They are the "sweat beads" of plants. This "perspiration", is a normal phenomenon for plants. Particularly on a hot, damp night with little wind when only a small amount of moisture evaporates while the roots continue to absorb a large amount of moisture as usual. Therefore extra moisture and other elements stream out of the stomas at the leaf ed , forming dew.