1955 年 68 巻 801 号 p. 86-93
Anatomical and morphological studies have been carried on the sporophytes, especially on the leaves, of Cheiropleuria bicuspis var. integrifolia from Hachijo Island. Gametophytes which persist imperfectly on some juvenile plants are also observed. There is an abundance of particular and primitive characteristics, such as, (a) the protostele showing a dorsiventrality in the dominant number of the protoxylem groups on its dorsal side ; (b) a marked dimorphism shown as the sterile and fertile leaves ; (c) firm and leathery laminas which are frequently bicusped at their tips and are provided with 4-6 parallel veins formed by repeated bifurcations of bundles of Marattia-type in the nor-articulated and wiry petiole, etc. An assortment of such characteristics of the sporophytes apparently shows an independent systematic position of Cheiropleuria among the Leptosporangiate ferns, and, thus, strongly supports the opinion of Nakai, who established an independent family Cheiropleuriaceae on the basis of some particular characteristics of the gametophyte.