The so-called trichomes on the leaves of the species of Croton studied correspond in reality to emergences.

The complex structural anatomy of these leaf emergences increases the surface area for absorption of atmospheric moisture.

We show experimentally that an aqueous solution can penetrate into the leaf emergences, continue through sclereids, and finally reach the vascular bundle or the mesophyll, maximizing water distribution in the leaf tissue.

Emergences likely play an important role in atmospheric water absorption in Croton species and might be one of the clues for the evolutionary success of this highly diverse Angiosperm genus.