Folioceros appendiculatus, a species widely distributed in the tropical regions of Asia and the South Pacific islands, was newly found in Tokunoshima Isl., southernmost part of Japan. The present species is characterized by the gemmae which densely cover the margins and dorsal surfaces of thalli, and the rather small spores with sparsely papillate proximal surfaces and with densely spinate-spinulate distal ones. Japanese material agrees well with that from more southern regions in the characteristics of gemmae, but spores show some unusual features; mature spores are rarely found and most spores remain united in a tetrad even in already dehiscent capsules. In addition to them, some smaller spores (24-28μm in diam.; up to 32μm in full mature spores) with more distinct triradiate marks are recognized. The presence of these unusual spores in Japanese material may suggest that spores of this species reach full maturity only with difficulty in the northern edge of its distributional range. Elaters of Japanese material also show unusual features in the form of cell-wall thickenings: besides extremely thick-walled elaters characteristic of the genus Folioceros, there exist many elaters which consist of not so thick-walled cells (they are suggestive of the elaters of Anthoceros or of those of intermediate conditions between Anthoceros and Folioceros). The presence of these elaters may give evidence for the idea that Folioceros is closely related to Anthoceros. All specimens are deposited in KYO.

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