Greek onyx - claw; referring to the shape of the frond lobes.

Rhizome short-creeping to long-creeping, thin, spreading on the soil surface with few branches, covered with scales. Sterile and fertile fronds similar. Fronds evergreen, divided 3 or more times and with numerous minute segments. Sori linear along the segment margins; indusium a marginal flap, generally meeting flap from other side of narrow segment.

c. 7 species of E Asia and America.

Division or spores.

Linear sori with flap-like indusia on both sides of the narrow, sharp-pointed terminal segments.

Source: Spencer, R. (1995). Adiantaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 1, Ferns, conifers & their allies. The identification of garden and cultivated plants. University of New South Wales Press.