Notes on the genus Crataegus L. (Rosaceae)
Some issues of designing a system of the genus Crataegus L. are observed. The idea of division the genus into 3 subgenera (Crataegus, Sanguineae Ufimov subgen. nov. and Americanae El Gazzar) and the section Crataegus into 3 subsections (Pentagynae (C. K. Sohneid.) Ufimov comb. et stat. nov., Azaroli (Loudon) Ufimov comb. et stat. nov. and Crataegus) is proposed. The lectotype of C. ambigua C. A. Mey. ex A. K. Becker is designated. Misusage of the name C. x browicziana K. I. Chr. for the hybrid between C. rhipidophylla Gand. and C. microphylla K. Koch is shown, and a new nothospecies C. x cispontica Ufimov nothosp. nova is described.