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

摘要

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