Rosemary leaf hairs. Coloured scanning electron micrograph (SEM) of the underside of a leaf of the herb rosemary, Rosmarinus officinalis. Numerous hairs (trichomes) cover the undersurface of the leaf. These unbranced multicellular hairs (brown) may have both a protective function against predators and serve to reduce evaporation from the leaf. Stomata or pores appear as small, green rounded structures (upper left); they serve to exchange gases from the leaf surface. Rosemary is both a herbal and medicinal plant used in cooking, in teas and wine, in perfumes, and as an astringent and disinfectant. Magnification: x750 at 6x7cm size.