The genus Conyza in Britain and a name for the hybrid between Erigeron acris and Conyza floribunda (Asteraceae)

The species of Conyza (Asteraceae) and their hybrids are briefly reviewed. A binomial name (x Conyzigeron stanleyi) is given for the hybrid between Erigeron acris L. and Conyza floribunda Kunth (including C. bilbaoana J. Rémy). The alien C. floribunda from South America has spread rapidly across Britain and Ireland since its initial records in 1992, and is now a common sight particularly in urban ruderal situations. Its hybrid with E. acris has now been found both in Ireland and several southern counties in England and is very likely to be found in further locations where both parents grow together.