A 2015 molecular study found that Asplenium nidus is polyphyletic, meaning that some populations were not closely related to others-A. nidus from Madagascar, Vanuatu and New Guinea were more closely related to other species than each other. Hence a revision with sampling of the species across its range was required to delineate the taxon and identify cryptic species.Asplenium nidus is an epiphytic species of fern in the family Aspleniaceae, native to tropical southeastern Asia, eastern Australia, Hawaii, Polynesia, Christmas Island, India, and eastern Africa. It is known by the common names bird's-nest fern (a name shared by other aspleniums) or simply nest fern.
Asplenium nidus forms large simple fronds visually similar to banana leaves, with the fronds growing to 50-150 centimetres (20-59 in) long and 10-20 centimetres (3.9-7.9 in) broad. They are light green, often crinkled, with a black midrib, and exhibit circinate vernation. Spores develop in sori on the underside of the fronds. These sori form long rows extending out from the midrib on the back of the outer part of the lamina (frond). The fronds roll back as they brown and create a massive leaf nest in the branches and trunks of trees.
Asplenium nidus is native to east tropical Africa (in Tanzania, inclusive of the Zanzibar Archipelago); temperate and tropical Asia (in Indonesia; East Timor; the prefecture of Kyushu, and the Ryukyu Islands of Japan; Malaysia; the Philippines; Taiwan; and Thailand); and in Australasia (in the northern part of Queensland in Australia).
Asplenium nidus can survive either as an epiphytal, or terrestrial plant, but typically grows on organic matter. This fern often lives in palm trees or bromeliads, where it collects water and humus in its leaf-rosette. It thrives in warm, humid areas in partial to full shade.
With a minimum temperature of 10 °C (50 °F), Asplenium nidus is widely cultivated in temperate regions as a houseplant. However, many plants sold in America as A. nidus are actually Asplenium australasicum, which has longer sori, and a differently shaped midrib. 'A. nidus has gained the Royal Horticultural Society's Award of Garden Merit.
Asplenium nidus has been used locally in folk medicine for asthma, sores, weakness, and halitosis.
The sprouts of A. nidus are eaten as a vegetable in Taiwan where it is called 山- (pronounced shān sũ) and typically cut into inch-long pieces and fried with garlic and chilli peppers.
In Hong Kong, this species is under protection based on Forestry Regulations Cap. 96A.