yucca

Any of a group of plants belonging to the lily family, with over 40 species found in Latin America and the southwestern USA. The leaves are stiff and sword-shaped and the flowers, which grow on upright central spikes, are white and bell-shaped. (Genus Yucca, family Liliaceae.)

Yuccas grow in dry soils where nitrate salts, required for protein manufacture, are in short supply. They have therefore evolved the ability to use ammonia, absorbed from animal urine, instead. Feeding extracts of yucca to livestock has been shown to reduce unpleasant ammoniacal smells from factory farms.