オキナウチワ,ヘラヤハズ,イトアミジ(褐藻,アミジグサ科)に於ける栄養繁殖

Results of the present writer's observations on vegetative propagation in Padina japonica Yamada, Dictyopteris prolifera (Okamura) Okamura and Dictyota linearis (C. Agardh) Greville (Dictyotaceae, Phaeophyta) are presented in this report.
Vegetative propagation in Padina japonica occurred solely from rhizomes. Gemmae were conical to subcylindrical and underwent apical growth at early stage of the development. Thereafter they became broader and compressed to flattened by replacing an apical cell to the marginal meristem. The meristem circinately inrolled towards the reverse side, then gemmae became typical fan-shaped and slightly calcified on the reverse side.
In Dictyopteris prolifera vegetative propagation occurred solely from the primary rhizoids. Gemmae were cylindrical to subcylindrical and underwent apical growth at early stage of the development. Thereafter gemmae became broader and compressed to flattened by replacing an apical cell to the marginal meristem.
In Dictyota linearis vegetative propagation occurred solely from the primary blade. Gemmae were conical to subcylindrical at early stage of the development, thereafter they developed into the flattened and dichotomously branched new blades. The growth of gemmae was apical throughout the development.
Vegetative propagation in those three species mentioned above was commonly occurred in August in the studied area.