Achimenes (Gloxinieae; Gesneriaceae) includes approximately 25 species of perennial herbs distributed from Mexico south through Central America to northern South America. Six sections are recognized: Achimenes, Dicyrta, Guthnickia, Locheria, Plectopoma, and Scheeria. These sections have traditionally been defined based on flower type/pollination syndrome. Flowers can be salverform, tubular, or funnelform in shape and red, yellow, purple, pink, or white in color. Additionally, some species have a distinct floral spur while others have no enlargement of the floral tube base. Phylogenetic relationships in the genus were explored using sequence data from the nrDNA internal transcribed spacer (ITS) and cpDNA trnL-F and trnE-T spacer regions. Results suggest that the large sections Achimenes and Dicyrta are polyphyletic. Some relationships supported by the molecular data correlate well with vegetative morphological characteristics. Patterns of floral evolution will be discussed.

Key words: Achimenes, floral evolution, Gesneriaceae, Gloxinieae, molecular phylogenetics