Carex foliosissima var. pallidivaginata (Cyperaceae), a new variety from Japan

Abstract

A new variety, Carex foliosissima F. Schmidt var. pallidivaginata J. Oda & Nagam., is newly described. It is distinguished from the type variety by the pale green basal sheaths, turning light brown on drying, and perigynia with invisible or inconspicuous veins. It is also distinct in the leaf anatomy; the leaves of the new variety are thinner and the second layer of bulliform cells (hinge cells) is thinner than that of var. foliosissima. Variety pallidivaginata is distributed from the upper beech forest zone to the subalpine zone on the Japan Sea side of central and northern Honshu, and in southernmost Hokkaido, at higher elevations than var. foliosissima which usually occurs from the lowland to lower montane zones. Variation in the leaf width of C. foliosissima was examined and the results did not support the wide leaved form ('var. latissima' Akiyama) as a distinct variety.