Blechnum amabile ("Osashida")

Japanese name: オサシダ （筬羊歯）
Scientific name: Blechnum amabile

[Overview]
An evergreen terrestrial fern growing on rocks in mountain forests and on rocky slopes.
It often grows in colonies.
The rhizome creeps; it either extends somewhat long with sparsely arranged fronds, or has short internodes and tufted fronds.
The rhizome bears scales.
The scales are narrowly ovate to broadly lanceolate, entire-margined, membranous, and brown.
The fronds are of two forms, sterile and fertile, both rather thick in texture.
The sterile fronds are lanceolate and once pinnate, about 20 cm long and 5 cm wide, with the tip narrowing abruptly into a tail-like extension; the stipe is 2–10 cm long, somewhat shorter than that of the fertile fronds, and pinnae that become small and ear-shaped are attached almost to the base.
The sterile fronds are narrowly lanceolate and once pinnate, about 20 cm long and 3 cm wide, with the tip narrowing abruptly into a tail-like extension; the stipe is 3–12 cm long, straw-colored, and often tinged reddish purple.
On the pinnae, the groove of the midrib on the upper surface is indistinct, and there is no ridge on the lower surface.
The sori are linear and extend long along the midrib of the fertile fronds.

[Notes]
The Japanese name compares the shape of the fronds to an osa (a reed, part of a loom used in weaving).

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