日本産南方系ホンダワラ属【8】コナフキモク Sargassum glaucescens

摘要

Sargassum glaucescens J. Agardh recorded firstly based on the specimen collected from Macao in south China is distributed in the tropical and subtropical regions. This species is characterized by: 1) discoid to scutellate holdfast and terete main branches with smooth surface; 2) liner lanceolate to lanceolate, and elliptical leaves with small dentate or smooth margin; 3) spherical vesicles, rarely with spines and wings on the surface of the vesicle and 4) dioecious receptacles with small leaf or vesicle. In Japan, this species growing on the subtidal rock in inner bay was recorded firstly in the Shimaura Is., Miyazaki Prefecture. This species is distributed mainly in south Kyushu. It is necessary to continue monitoring it about the distribution of S. glaucescens which is distributed in the border area of the algal flora, to sense an environmental change.