in botany; a genus of plants belonging to the class of syngenesia, and to the order of polygamia aquilis. The common calyx is erect; the leaflets numerous, sub-equal, and oblong, the two exterior being longer than the rest. The compound corolla is uniform and tubular; the florets are hermaphrodite and equal; the proper corolla is funnel-shaped. The filaments are five in number, and short. The antherae cylindrical and tubular. The seeds are vertical, oblong, flat, and covered with chaff. The receptacle is paleaceous and conical. There are seven species, the urens, pseudo-acemella, acemella, salivaria, atriplicifolia, insipida, and oleracea.