Heather leaf stomata. Light micrograph of a transverse section through a stomata (centre, circular) in the leaf of a heather (Erica sp.) plant. Heather is a drought plant (xerophyte). Xerophytes have evolved an anatomy that cuts down water loss through transpiration. The epidermis consists of thick-walled cells covered in a thick waxy cuticle (top, light-pink/white). The stomata are sunken and the cup above each stoma traps moist air. Magnification: x234 when printed 10 centimetres wide.