Mediterranean Subspecies versus Californian Varieties: An Example from Acmispon (Leguminosae, Loteae)

Abstract

The tribe Loteae of the family Leguminosae has major centers of diversity in the Mediterranean Region and California. It is used here to illustrate different traditions of taxonomic interpretation of infraspecific variation among researchers in different continents. Recent accounts of European and Mediterranean taxa commonly make an emphasis on recognizing subspecies. In contrast, accounts of North American Loteae recognize all infraspecific taxa as varieties. Harmonization of taxonomic concepts across continents is essential for a more accurate representation of data in global biodiversity databases. It is reasonable to use the rank of subspecies for geographically defined infraspecific units with localized zones of intergradation. Such subspecies may be at least partially compatible across continents and taxonomic groups. In the present paper, we discuss taxa traditionally included in or associated with Acmispon glaber (Vogel) Brouillet (=Syrmatium glabrum Vogel) and demonstrate a need for recognizing three species, of which one has three geographically defined subspecies. Required nomenclatural combinations are proposed. It is proposed that subspecies rather than varieties should be recognized in a number of other species of North American Loteae (and other plant groups). Inland subspecies of Acmispon glaber and A. maritimus offer an opportunity for comparative analysis in an eco-evo-devo framework.