Two New Species of Carex (Cyperaceae) from the Ogasawara (Bonin) Islands, Japan

Abstract

Two new species of the genus Carex L. (Cyperaceae) from the Ogasawara (Bonin) Islands, C. chichijimensis Katsuy. and C. yasuii Katsuy., are described. C. chichijimensis belongs to sect. Graciles Tuck. ex Kük. and is closely related to C. hattoriana Nakai which is endemic to the Ogasawara Islands, but differs from the latter in having larger, rather glabrous and strongly veined perigynia. C. yasuii belongs to sect. Mitratae Kük. and resembles C. gracilispica Hayata and C. rhynchachaenium C. B. Clarke from Taiwan in having gourd-like lanceolate, more than 4.5 mm long perigynia, and stoutly stipitate, cylindrically necked achenes. However, C. yasuii is easily distinguished from the latter two species by longer culms, narrowly ovate pistillate scales with acuminate and short aristate apex and glabrous perigynia. Both C. chichijimensis and C. yasuii are found only in Chichijima Island.