イワデンダ科コウヤワラビ属の夏緑性シダ類で、学名は Onoclea orientalis (syn. Pentarhizidium orientale)。英名はありません。
The "Inu-gansoku" (Onoclea orientalis) belongs to the family Woodsiaceae. It is a summer-green fern that is distributed to Japan and East Asia. This fern grows in montane woodlands, dales and roadsides, and it can reach 50-120 cm in height. The leaves are consist of sterile fronds and fertile fronds. The sterile fronds are once pinnatly compound and the pinnae are lobate. The fertile fronds are stout, hard and remain through winter. The Japanese name is because the shape of this sporophyll resembles "Gansoku" (Ostrich fern). It is often used for flower materials. It is called "東方莢果蕨" in Taiwanese Huayu and "東方莢果蕨" (dong fang jia guo jue) in Chinese.