Pellaea rotundifolia, the button fern, is a species of fern endemic to New Zealand, where it grows in scrub and forests. It is also a popular garden plant (in zones 8 and 9) and house plant. Pellaea rotundifolia is an evergreen fern that can have more than 30 pairs of round, dark-green, leathery pinnae on fronds up to 18 in. (45 cm). It needs acidic and well-drained soil; it does not appreciate the moist, humid conditions that most ferns require so does well with minimal watering.