Trichomes (/ˈtraɪkoʊmz, ˈtrɪkoʊmz/); from Ancient Greek τρίχωμα (tríkhōma) '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.