Phylogenetic and Taxonomic Studies on Helonias, Ypsilandra and Heloniopsis III. Taxonomic Revision

Abstract

The three genera, Helonias, Ypsilandra and Heloniopsis have not sufficient differences to be distinguished from each other in generic rank. Accordingly the three genera were unified into one genus. Heloniopsis and Ypsilandra were reduced to Helonias. The following taxonomic reductions were also made in this paper; i.e., both Y. cavaleriei and Y. kansuensis were reduced to Helonias thibetica; both Heloniopsis arisanensis and Heloniopsis taiwanensis to Helonias umbellata; Y. yunnanensis var. himalaica to Helonias yunnanensis; Sugerokia nipponica, Heloniopsis japonica var. flavida, H. japonica var. albiflora and H. japonica var. tessellata to Helonias breviscapa. Floral colour variants were not distinguished as distinct taxa. As a result, a total of nine species were recognized in the emended Helonias. Eight new names were produced as a consequence of the transference of both Ypsilandra and Heloniopsis to Helonias.