A re-assessment of the taxonomy of Lens Mill. (Leguminosae, Papilionoideae, Vicieae)

Abstract

Three taxonomic problems exist within the genus Lens. The first is the lark of agreement on classification and rank at the specific and sub-specific levels; the second involves the relationship between the recently distinguished L. lamottei and L. odemensis or L. tomentosus and the third is the unreliability of stipule orientation as the primary character to distinguish between L odemensic and L. nigricans. The objectives of this study were to address these problems by investigating the classification of Lens in the light of evidence relating to crossability and phenetic relations, to idcntify morphological markers for taxon delimitation within the genus Lens, with special reference to L. lamottei, L. nigricans and L. odemensis, and to determine whether the taxon delimitation is supported by isozyme and RAPD evidence. As a result of these studies two new combinations are proposed, with L. odemensis and L. tamentosus being reduced to sub-species of L. culinaris. A classification, key and descriptions of the accepted taxa within the genus are presented.