Adiantum formosum, known as the giant maidenhair or black stem maidenhair is a fern found in Australia and New Zealand. It was one of the many species authored by Scottish botanist Robert Brown, appearing in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen. Its species name is the Latin adjective formosus "handsome" or "beautiful". Easy to grow in cultivation, Adiantum formosum makes a good subject for container gardening. It appears to go dormant in cooler months and grow rapidly during the summer. A smaller, variegated form is commercially available and cultivated.