in botany: A genus of plants belonging to the class of syngenesia, and to the order of polygamy superflua; and in the natural system ranging under the 49th order, Compositae. The receptacle is paleaceous; the pappus is wanting; the exterior calyx is pentaphyllous, proper, and spreading; the radius is halved. There are three species: 1. The orientalis, which is a native of India and China. 2. The occidentalis, which is a native of Virginia. 3. The flocculosa, a native of Peru.