Geum × convallis (G. macrophyllum × G. urbanum, Rosaceae): a new Geum hybrid from England

Abstract A new Geum L. hybrid, Geum macrophyllum Willd. × G. urbanum L., has been found in England and is here described as G. × convallis M.P. Wilcox. The holotype is described from the original site in Shipley Glen (Mid-west Yorkshire), but it has also been found in Rochdale (South Lancashire) and Wythenshawe Park (Cheshire). Previous and recent studies on Geum hybrids have shown that G. × convallis is highly sterile, contrasting strongly with our native introgressive G. rivale L. × G. urbanum L. (G. × intermedium Ehrh.). In 1959, G. macrophyllum × G. urbanum (G. ×  gajewskii Smejkal) was incorrectly described from Brno, in the Czech Republic. The diagnostic features of the new hybrid are described and illustrated.