<i>Carex tokuii</i> (Sect. <i>Mitratae</i>, <i>Cyperaceae</i>), a New Species from Japan and Korea

<p>Carex tokuii J. Oda & Nagam. is described from Japan and Korea. This species is very similar to C. rugata Ohwi in having pale green scales, glabrous perigynia, and especially achenes concave at the middle of three faces. However, this species is easily distinguished from C. rugata by many quantitative characters. The length of staminate and pistillate scales, length of staminate and pistillate spikes, length of leaf blades of lowermost bract, number of pistillate spikes per culm, length of culms, leaf width and length of achenes are usually larger in C. tokuii than C. rugata. Moreover, C. tokuii and C. rugata showed different qualitative achene morphology. The stipes of achenes are nearly straight (rarely ascending) to the base in C. tokuii, while they are curved abruptly in C. rugata (rarely ascending). The central silica bodies on achene epidermis are large and well developed in C. tokuii, but are small and sometimes invisible in C. rugata. Habitat and habit of rhizomes also tend to differ from each other. Carex tokuii grows at mesic forest edge, while C. rugata grows in rather wet places near stream or marsh. The rhizomes are caespitose in C. tokuii, but are loosely tufted and sometimes long-ascending, forming matted populations in C. rugata. Carex tokuii is distributed in Shikoku (southwestern area of Ehime Pref.) and Kyushu (Tsushima, Nagasaki Pref., and Sakurajima, Kagoshima Pref.) in Japan, and Gwangju-shi and Jeollanam-do in South Korea.</p>