The systematic position ofCubanthusand other shrubby endemic species ofEuphorbia(Euphorbiaceae) in Cuba

[摘要] Cubanthus(Euphorbiaceae) has traditionally been recognized as a small genus of three similar species restricted to Cuba and Hispaniola. In this study we used DNA sequence data from the nuclear ITS and chloroplastndhFgene regions to investigate its systematic position and the position of four other shrubbyEuphorbiaspecies endemic to Cuba:E. cubensis, E. helenae, E. munizii , andE. podocarpifolia . The results demonstrate that all of these taxa belong to a well-supported Antillean clade nested withinEuphorbiathat also includesE. puniceaandE. gymnonota . For that reason, we treatCubanthusas a section ofEuphorbiainstead of a separate genus.Euphorbiasect.Adenorimais relegated to a synonym of sect.Cubanthus . New names are proposed forCubanthus brittoniiandCubanthus linearifolius( Euphorbia millspaughiiandE. scutiformis , respectively), and a new combination is made forCubanthus umbelliformis( Euphorbia umbelliformis ). SectionCubanthusbelongs to clade C ofEuphorbiaand is part of a New World assemblage that includes members of sectionsEuphorbiastrum, Pteroneurae, Portulacastrum, Stachydium , and the former genusPedilanthus . Based on both the molecular results and morphological differences, two subsections are proposed: subsect. Cubanthus and subsect.Moa . The molecular phylogeny supports the hypothesis that sectionCubanthusradiated entirely within the Antilles and the nearby Bahamian archipelago.

[学科分类] 植物学

[关键词] Antilles;Cuba;Cubanthus;Euphorbia;molecular phylogeny