While the surfaces of leaves may appear smooth, they are a structurally complex micro-environment. Trichomes, or leaf hairs, grow on the surface of leaves and may enhance foliar uptake of fog water during the summer drought in coastal California.
This Environmental Scanning Electron Microscope (ESEM) image of the leaf surface from the native shrub Purple Sage (Salvia leucophylla) is composed of many trichomes (leaf hairs) approximately 50 micrometers in diameter. These trichomes are what give the leaves a whitish hue, reflecting sunlight and reducing water loss. This native shrub benefits from coastal fog during the dry summer months and takes in water through their leaves. The trichomes pictured here may facilitate water uptake from the leaf surface.