The genus Rhynchotechum (Gesneriaceae) in Taiwan is revised based on a critical morphological study. Three species and one form are recognized. A new species, Rhynchotechum brevipedunculatum J. C. Wang sp. nov., is here described from Taiwan. After comparing with R. discolor in detail, R. discolor var. incisum (Ohwi) Walker can be distinguished from the former only in having incised leaves. Therefore, the taxon is reduced to the rank of form and a new combination, R. discolor forma incisum (Ohwi) Hatusima ex J. C. Wang comb. nov., is proposed here. Calyx-segments shape and inflorescence patterns are shown to be the most useful characters for the classification of Taiwan species. In addition, seed coat micromorphology under scanning electron microscope displays more or less interspecific variation. The meiotic chromosome numbers of all Taiwanese taxa are counted in this paper. All taxa, of which three are determined for the first time, have the same chromosome number (n=10). A key to the taxa of this genus in Taiwan along with description, taxonomic notes, and a line drawing are provided.
The Genus Rhynchotechum Blume (Gesneriaceae) in Taiwan