Biogeographic, Taxonomic, and Cladistic Relationships Between East Asiatic and North American Crataegus

Thegenus a -some 150 species, more or less, treated.anthae (mainly European, of about 25 species) and of the largest series: Oxyac Azaroli E to Ce dcr Asiatic, of n 12 species) do not at first sight 5 x s C. x of Yunnan be aligned in a North mi ecognized in about 20 series or sections, some of which, whi d Apiifoliae, is Met similar to European Oxyacanthae, aff ana to be not only among the most t nity with Pyracantha and that of other iade with M impinge on the se C. scabrifolia.Most other North r.Thei esp i indicates basal possibilities an -temperate * genus.One is thus led to postulate ap origin that was able to cross Beringia i in the early T Tertiary or i Mi ad Thence d d from a south China relictual base evolution toward th OGI IYU wit spread i into western Eurasia (one major -line); A pes thro ugh Beringia to a North American hA Hm iss are conspecific.Also, except for the postulated ancient relicts, no Chinese stock.closely rela ted.rni Wn deciding what materials on the list ef ascinating and complex genus Crarating : t be presented for the St. Louis Sysine pasim. in 1982 I had to come to --Ow to handle incomplete work.My cg sh puaeealy influenced by the view that as received no comprehensive treaten "a E modern and effective.