Overview
Adiantum cunninghamii
Recognition: smallish ground fern, with oblong frond segments. The undersides of the fronds are bluish-green. This, combined with the lack of hairs on the stems and indusia (the indusia protect the spore producing sporangia and in Adiantum comprise inrolled frond margins), the kidney-shape of the indusia, and the corner rather than central attachment of the ultimate frond segments distinguishes Cunningham’s maidenhair from other maidenhair (Adiantum) ferns in New Zealand.
Distribution/ecology: only found in New Zealand. In lowland forest throughout, often on banks. Especially common on limestone.
Relationships: seven indigenous and two exotic Adiantum species are found wild in New Zealand. They are distinguished from each other by the distribution of hairs, frond shape, and form of the reproductive structures. Of the indigenous species, three are only found in New Zealand, one also occurs in Australia, while the others are widespread and extend through the southern Pacific and as far as Africa.
Adiantum is distributed nearly worldwide and includes about 200 species. ‘Maidenhair’ is variously thought to allude to the branching stems of the fronds of some species or to the fine hairs on the roots. Adiantum is part of the Pteridaceae fern family, whose other indigenous New Zealand representatives are Anogramma, Cheilanthes, Pellaea, and Pteris.