Adiantum formosum, commonly known as Giant Maidenhair or Black Stem Maidenhair, is a semi-evergreen fern native to the understory of rainforests and moist, shaded areas along streams in Queensland, New South Wales, and Victoria, Australia, as well as the forests of New Zealand. It can reach up to 47 inches (120 cm) in height with fronds supported by striking black stems that can be up to 35 inches (90 cm) long. This fern typically forms lush, delicate clumps of triangular fronds that are highly ornamental.

Giant Maidenhair is valued for its elegant appearance and adaptability to cultivation, especially in moist, shaded garden areas or as a refined choice for container gardening. It thrives in humid conditions with indirect light, making it suitable for indoor environments as well. In cultivation, it requires consistently moist soil with good drainage and prefers a rich, organic medium. While it is relatively easy to maintain, it is sensitive to cold and drying winds. The variegated form adds a unique visual interest to shade gardens or as a houseplant. It is not known for significant pest or disease problems, but overwatering can lead to root rot.CC BY-SA 4.0