Taxonomic relationships in eight species belonging to five of the 13 currently recognized sections of the genus
Lathyrus have been discussed and their phylogeny based on chromosomal criteria is suggested. A diploid
number of 2n = 14 (x = 7) has been found in all species studied and thus x = 7 is confirmed as the basic number
in the genus. Karyotypes of the examined species have metacentric and submetacentric chromosomes that are
variable in length. The retention of L. pratensis in the section Pratensis is confirmed. The assignment of L.
hirsutus to section Lathyrus and of L. cicera and L. sativus to section Clymenum are supported. The present data
revealed that L. pratensis is the most likely ancestral type in the genus and that Layhyrus represents a natural
monophyletic group in the tribe Vicieae.