Figure 3.13 Structural adaptations of plants against heat and drought. (a) Spines and hairs on leaf surfaces, such as in the silverleaf sunray plant, shade the plant from direct sunlight and reduce evaporation. (b) Finely divided leaves, as found in the mesquite plant, help dissipate any built-up heat. (c) Stomata that are recessed into deep pits containing hairs, as in the oleander plant, slow the evaporation rate of water out of the leaf.