Underside

Alarm leaves (Populus alba). In this case, as in many others, the perverse is distinguished because it is clearer than the beam.

In botany, the underside or abaxial face of the leaf blade of a plant is called the underside. The epidermis of the underside is usually different from that of the beam or upper face; It almost always presents a thinner cuticle, greater density of stomata, and frequently also a greater abundance of trichomes (epidermal hairs). It is almost always lighter in color than the beam.