Abstract

Until recently, classification of Crataegus (Maleae, Rosaceae) has been mostly based on morphological data. Phenetic and cladistic approaches allowed taxonomists to establish classifications of the genus at the levels of sections and series, but without revealing clear phylogenetic relationships between these infrageneric groups. Molecular studies suggest the existence of major evolutionary lineages, some of which correspond to previously published subgenera (C. subg. Americanae, subg. Crataegus, and subg. Sanguineae). The present paper aims to complete the subgeneric classification of Crataegus by raising C. sect. Mespilus and sect. Brevispinae to subgenera. Also, in order to depict current knowledge of the phylogenetic relationships within C.subg. Sanguineae, a new C. sect. Salignae is described. In addition, we provide a new description of Crataegus and keys to distinguish it from other related Maleae genera, to determine the subgenera and, within C.subg. Sanguineae, to determine the sections. In conclusion, we summarize the current classification of Crataegus, excluding nothosubgenera and nothosections, in relation to the phylogeography and leaf venation patterns of the genus.