Hymenophyllum nephrophyllum

Hymenophyllum nephrophyllum, commonly known as the kidney fern, is a filmy fern species native to New Zealand. It commonly grows on the forest floor of open native bush. Individual kidney-shaped fronds stand about 5–10 cm tall. In hot weather they shrivel up to conserve moisture, but open up again when the wet returns. This species has very thin fronds which are only four to six cells in thickness. In the Māori language they are also called raurenga. A specific example of occurrence of H. nephrophyllum is within forested areas of Westland, New Zealand, where it occurs with other fern species including crown fern, Blechnum discolor....read more on Wikipedia.