おおさとめしだ (大里雌羊歯) [Index] [Back] わが国の固有種で、本州の東北地方南部から四国・九州に分布しています。「さとめしだ（里雌羊歯）」と「やまいぬわらび（山犬蕨）」との自然交配種です。山地の林床や湿地に生え、高さは７０〜１００センチになります。葉は全体に大型で、３回羽状深裂から３回羽状複葉、緑色の草質です。葉柄や中軸は紅紫色を帯びています。胞子嚢群は、葉の裂片の辺縁寄りにつき、長楕円形や鉤形などの形です。包膜の辺縁は、細裂から波縁までと変化が多いです。 イワデンダ科メシダ属の夏緑性シダ類で、学名は Athyrium x multifidum (syn. Athyrium deltoidofrons var. multifidum)。英名はありません。 The "Oo-sato-meshida" (Athyrium x multifidum) belongs to the family Woodsiaceae. It is a summer-green fern that is a species endemic to Japan, distributed from the southern part of the Tohoku region of Honshu to Shikoku and Kyushu. It is a natural hybrid of "Satome-shida" and "Yama-inu-warabi". It grows on the forest floor and in wetlands in mountainous areas, reaching a height of 70 to 100 cm. The leaves are generally large, ranging from deeply 3-pinnately lobed to 3-pinnately compound, and are green and herbaceous. The petioles and midribs have a reddish-purple tint. The sori are located near the margins of the leaf lobes and are oblong or hook-shaped. The margins of the spore covers vary widely, ranging from finely lobed to wavy. 熊本県高森町「阿蘇野草園」にて、2026年05月13日撮影。 Shu Suehiro shu@botanic.jp