The Japanese beech fern (Thelypteris decursive-pinnata) belongs to the Thelypteridaceae family. It is a summer-green fern that is native all over Japan, the southern Korean Peninsula, China, Taiwan, the Indo-China Peninsula and India. This fern grows in mountain forest edges or stone walls, and can reach 20-50 cm long. The leaves are unipennate to twice deep pinnately. The pinnae are lanceolate and the underneath pinnae are shorter than other parts.