つるでんだ (蔓連朶) [Index] [Back] わが国の各地をはじめ、朝鮮半島や中国、ロシア東部に分布しています。山地のやや湿った岩上や斜面などに着生し、高さは２０センチほどになります。ふつう群生します。葉は１回羽状複葉で、中軸や葉柄は褐色の鱗片をやや密につけます。羽片はふつう２０〜３５対がつき、卵状長楕円形です。中軸の先端は長く伸びて無性芽を生じます。ソーラスは辺縁よりに１列に並び、包膜は大きな円形です。  オシダ科イノデ属の常緑性シダ類で、学名は Polystichum craspedosorum。英名はありません。  "Tsuru-denda" (Polystichum craspedosorum) belongs to the family Dryopteridaceae. It is an evergreen fern that is distributed not only in various parts of Japan, but also in the Korean Peninsula, China, and eastern Russia. It grows on slightly moist rocks and slopes in the mountains, and is about 20 cm high. It usually grows in clusters. The leaves are once pinnatly compounds, and the rachis and petioles are slightly densely covered with brown scales. The pinnae usually have 20 to 35 pairs and are ovate-oblong. The tip of the rachis grows long and produces asexual buds. The sporangia (solus) is lined up in a row from the edge, and the indusia are large circle.  宮城県仙台市青葉区「蕃山」にて、2021年04月15日撮影。  Shu Suehiro shu@botanic.jp