bur

A bur entangled in a fox's fur. By the time the animal grooms itself and discards the bur it will probably have transported it some distance. A number of plants, including the burdock (shown here), disperse their seeds in this way.

In botany, a type of ‘false fruit’ or pseudocarp, surrounded by numerous hooks; for instance, that of burdock Arctium, where the hooks are formed from bracts surrounding the flowerhead. Burs catch in the feathers or fur of passing animals, and thus may be dispersed over considerable distances.

The term is also used to include any type of fruit or seed with hooks, such as that of sandbur Cenchrus, a grass, and white avens Geum canadese.