A maidenhair fern.
maidenhair fern definition by American Heritage Dictionary
Any of various ferns of the genus Adiantum, having purplish to black stalks, usually feathery fronds, and delicate fan-shaped leaflets with marginal sori.
Origin: From the fineness of its stems.
Variant of maidenhair
any of a genus (Adiantum) of ferns with delicate fronds and slender black stalks
also maidenhair fern