Conyza (horseweed, butterweed or fleabane) is a genus of flowering plants in the family Asteraceae.Lessing, Christian Friedrich. 1832. Synopsis Generum Compositarum 203–204 in LatinTropicos, Conyza Less.Cronquist, A. 1943. The separation of Erigeron from Conyza. Bull. Torrey Bot. Club 70: 629–632. 1943.Nesom, G. L. 1990c. Further definition of Conyza (Asteraceae: Astereae). Phytologia 68: 229–233.
They are native to tropical and warm temperate regions throughout the world, and also north into cool temperate regions in North America and eastern Asia. The New World species of the genus are closely related to Erigeron (also known as fleabanes).Flora of North America, Horseweed, Conyza Lessing
The species are annual or perennial herbaceous plants, rarely shrubs, growing to tall. The stems are erect, branched, with alternate leaves. The flowers are produced in inflorescences, with several inflorescences loosely clustered on each stem.
Many species of the genus Conyza are ruderal species and some have been found to be resistant to the herbicide glyphosate.
Species
References
External links Germplasm Resources Information Network: Conyza Chinese plant names: Conyza