1969 年 82 巻 978 号 p. 482-487
Karyological studies were made on Japanese ferns of 4 taxa belonging to the Polypodiaceae. These chromosome numbers are as follows; Lemmaphyllum microphyllum var. microphyllum 2n=72, L. microphyllum var. obovata 2n=72, Pyrrosia linearifolia 2n=72, P. lingua 2n=72. Karyotype analysis were made on 3 taxa. Each of the chromosome complement can be divided morphologically into 6 (A-F) types, and each type can be further divided into 2 groups. Therefore, the basic number (b) in this study can be considered to be 12. Relation between b=12 and b=11 in ferns is discussed. As found in 2 genera (Hymenophyllum and Mecodium) of Hymenophyllaceae (Tatuno and Takei10) b=11 may have derived from b=12, as found in the genus Lemmaphyllum and Pyrrosia of Polypodiaceae.