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a genus of low annual or perennial herbs and—less commonly—subshrubs of the family Compositae. The alternate leaves are deeply or delicately pinnatisect and frequently aromatic; the inflorescences are large solitary heads on long peduncles. The receptacle is membranous. The ray flowers are yellow or orange, and the disk flowers are yellow or purple-brown. There are more than 60 species, distributed mainly in southern Africa. One species occurs in Ethiopia. Annual varieties, mainly U. anethoides and U. versicolor, are used in floriculture.