Trichomes ( or ), from the
Greek τρίχωμα (trikhōma) meaning "
hair", are fine outgrowths or appendages on
plants,
algae,
lichens, and certain
protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant is an
indumentum, and the surface bearing them is said to be
pubescent.