Geographical Distribution and Variation of Bistortil tenuicaulis and its New Variety from Japan, with Special Reference to Gynodioecy of B. tenuecaulis and B. abukumensis (Polygonaceae)

Abstract

Geographical distribution and morphological variation of Bistorta tenuicaulis (Bisset & S. Moore) Nakai are examined. Two types of plants are recognized in the species by the differences in rhizomes, radical leaves, inflorescences, pedicels and sex expression patterns. Plants from the Japan Sea side regions of central to western Honshu are recognized as a new variety, var. chionophila Yonekura & H. Ohashi. Gynodioecy of B. tenuicaulis is reported for the first time and compared with that of B. abukumensis.