Awn (botany)

An awn is a hairy or bristle-like growth on a plant.

On the seeds of grasses such as barley or rye, they form foxtails which assist seed dispersal by being barbed and so sticking to passing animals. Also, the awns may twist or curl as they are wetted and dry out and this action can make fallen seeds walk until they fall into a crevice into which they then burrow.

Besides grasses, other families of plants which have awns include Asteraceae such as sunflowers and Geraniaceae such as geraniums. In the latter, the awns help disperse the seeds by developing a tension which then catapults the seeds when the seed head ripens and dries out.