Alpine water fern.
Blechnum penna-marina is a native alpine water fern that can grow in conditions down to -25°C. It natural range in New Zealand is the North, South, Stewart, Chatham, Antipodes, Auckland, Campbell Islands and the Macaquarie Island. Its habitat is coastal to alpine in open forest, subalpine scrub, grassland, alpine herbfield, and in moss field on the shaded sites of rock outcrops. It mostly montane to alpine in the northern part of range, and is scarce north of the Bay of Plenty and the Waikato. It is present on Mt Egmont/Taranaki. It also grows in Australia, some Pacific islands, South America. It is evergreen and its fronds can grow to 20 cm and have a width of 2 cm. Frond height decreases with altidude to a few centimetres near the upper limit of its range. Original public domain image from Flickr