Kidney Fern New Zealand. - Kidney Fern, Trichomanes Reniforme, Is A Filmy Fern Species Native To New Zealand. It Commonly Grows On The Forest Floor Of Open Native Bush. Individual Kidney-shaped Ferns 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 Photo