ИСТИНА

The genus Lotus includes about 120 species widespread in Macaronesia, Europe, Africa, Asia, Australia, and on Pacific islands. Section Lotus is one of the most problematic within the genus; more than 100 species have been described but the majority of them were later transferred to synonyms. Clearly, a new taxonomic revision of the section Lotus is needed. The section unites species with five-leaflet leaves, predominantly yellow petals, almost actinomorphous or slightly zygomorphous calyx, papillate stylodium, multiseeded dehiscent fruit with endocarpium without brown cells, basic chromosome number x=6. A phylogenetic study of the genus Lotus and related genera based on nrITS1,2 data revealed that the section Lotus was not monophyletic. It formed a common clade with members of sections Dorycnium and Bonjeanea. Similar results were obtained in a phylogenetic study of the tribe Loteae based on psbA-trnH cpDNA, where section Lotus was combined with section Bonjeanea. An analysis of nrITS and morphological data showed the monophyly of the section Lotus (including L. conimbricensis). The largest group within the section Lotus is the Lotus corniculatus group (LC). In a phylogenetic analysis of nrITS data this group was monophyletic. Morphological studies of LC group revealed diploid and tetraploid taxa morphologically close to L. corniculatus or more distant from it. Interspecific hybridization are supposed to take place in this group. According to nrITS data, the Lotus angustissimus group (LA) was not monophyletic, some of its species were combined with species of LC group. Lotus pedunculatus group possesses a combination of characters which make it close both to LC and LA groups. Relationships within and between LC and LA groups and taxonomic position of several species are discussed.