Two New Species of Carex sect. Capitellatae (Cyperaceae) from Japan

Abstract

Carex ruralis J. Oda & Nagam. and C. koyaensis J. Oda & Nagam. (sect. Capitellatae) are described from Japan as new to science. These species are similar to C. capillacea Boott, but C. ruralis is distinct from C. capillacea in having fewer (4-8) pistillate flowers, leaves narrower (0.5-0.8 mm wide) and involute to trigonous, and perigynia lacking glandular dots. Carex koyaensis is distinct from C. capillacea in having rhizomes long creeping, culms shorter (10-20 cm long), leaves recurved, and perigynia weakly nerved and without glandular dots. Both species are also distinct from C. capillacea in the achene micromorphology. The cellulose anticlinal walls of C. capillacea are exserted beyond the silica deposits, while those of C. ruralis and C. koyaensis are entirely covered by the silica deposits. The satellite bodies of Carex ruralis and C. koyaensis are smaller and fewer than those of C. capillacea. Moreover C. koyaensis often has a honeycombed anticlinal wall. A key to the Japanese species of Carex sect. Capitellatae is provided.