Viola tokaiensis (Violaceae), a New Species from Japan

Abstract

A new species, Viola tokaiensis Sugim. ex N.Yamada & Igari (Viola L. sect. Patellares (Boiss.) Nakai) is described. This species has long been confused with V. boissieuana Makino which is widely distributed in the warm temperate region of Japan as well as the southernmost part of South Korea, but is easily distinguished by the leaf lamina wider than its length and equipped with more numerous distinct teeth on the margin, the larger, often 2-dentate appendage of sepals, the subglabrous base of lateral petals and the nearly wingless columnar style. The morphology of the style indicates its closer affinity with V. selkirkii Pursh ex Goldie. Viola tokaiensis is confined to forest floors of the cool-temperate zone in the Tokai Region of central to eastern Honshu and disjunctly in the mountain region of Shikoku with higher elevation than V. boissieuana.