- See bird's-nest fern for other plants with this common name.
Asplenium nidus is an epiphytic species of fern in the family Aspleniaceae, native to tropical southeastern Asia, eastern Australia, Hawaii (ʻēkaha in Hawaiian), Polynesia, Christmas Island, India, and eastern Africa. It is known by the common names bird's-nest fern (a name shared by some other aspleniums) or simply nest fern.
|Asplenium nidus in the Philippines|
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, with occasional individuals up to 6.6 feet (two meters) in length by up to two feet (61 centimeters) width  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.
A global phylogeny of Asplenium published in 2020 divided the genus into eleven clades, which were given informal names pending further taxonomic study. A. nidus belongs to the "Neottopteris clade", members of which generally have somewhat leathery leaf tissue. While the subclades of this group are poorly resolved, several of them share a characteristic "bird's-nest fern" morphology with entire leaves and fused veins near the margin. Both the 2020 study and a 2015 molecular study found that A. 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. A. nidus sensu lato forms a clade with the morphologically similar A. australasicum, but other bird's-nest ferns such as A. antiquum and A. phyllitidis form a separate subclade which is not particularly closely related.
Asplenium nidus is native to east tropical Africa (in Tanzania, inclusive of the Zanzibar Archipelago); temperate and tropical Asia (in Indonesia; East Timor; the island 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 epiphyte or terrestrial plant, but typically grows on organic matter. This fern often lives in palm trees, where it collects water and humus in its leaf-rosette. It thrives in warm, humid areas in partial to full shade. It dislikes direct sunlight and likes to be in full shade on the north facing garden wall.
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. Asplenium nidus has gained the Royal Horticultural Society's Award of Garden Merit.
The sprouts of A. nidus are eaten as a vegetable in Taiwan where it is called 山蘇 (pronounced shān sũ) and typically cut into inch-long pieces and sautéed with garlic and chilli peppers.
In Hong Kong, this species is under protection based on Forestry Regulations Cap. 96A.
- Asplenium nidus was first described and published in Species Plantarum 2: 1079. 1753. "Name - !Asplenium nidus L." Tropicos. Saint Louis, Missouri: Missouri Botanical Garden. Retrieved November 3, 2011.
- "Name - !Asplenium nidus L. synonyms". Tropicos. Saint Louis, Missouri: Missouri Botanical Garden. Retrieved November 3, 2011.
- Mary Kawena Pukui and Samuel Hoyt Elbert (2003). "lookup of ʻēkaha". in Hawaiian Dictionary. Ulukau, the Hawaiian Electronic Library, University of Hawaii Press.
- NPS. "Kapahulu Coastal Strand" (PDF). Haleakalā National Park Plant Communities. Retrieved January 11, 2017.
- MacDonald, Elvin "The World Book of House Plants" pp.264 Popular Books
- MacDonald, Elvin "The World Book of House Plants" pp.263 Popular Books
- Chandra, S.; Fraser-Jenkins, C.R.; Kumari, A. & Srivastava, A. "A Summary of the Status of Threatened Pteridophytes of India. Taiwania, 53(2): 170-209, 2008" (PDF). Retrieved August 2, 2017.
- "Asplenium nidus". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved November 3, 2011.
- Copeland, Edwin B. (1960). Fern Flora of the Philippines - Volume 3. Manila: Bureau of Printing. p. 450.
- Linnaeus, C. (1753). Species Plantarum. Vol. II (1st ed.). Stockholm: Laurentii Salvii. p. 1079.
- Xu et al. 2020, p. 27.
- Xu et al. 2020, p. 31.
- Xu et al. 2020, p. 41.
- Ohlsen DJ, Perrie LR, Shepherd LD, Brownsey PJ, Bayly MJ (2015). "Phylogeny of the fern family Aspleniaceae in Australasia and the south-western Pacific". Australian Systematic Botany. 27 (6): 355–71. doi:10.1071/sb14043.
- "Bird's Nest Fern". Our House Plants.
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 978-1405332965.
- R. J. Johns, in the 2001 Flora Malesiana Symposium[full citation needed]
- "RHS Plant Selector - Asplenium nidus". Retrieved 5 June 2013.
- James A. Duke. "Asplenium nidus (ASPLENIACEAE)". Dr. Duke's Phytochemical and Ethnobotanical Databases. Retrieved December 24, 2017.
- Xu, Ke-Wang; Zhang, Liang; Rothfels, Carl J.; Smith, Alan R.; Viane, Ronald; Lorence, David; Wood, Kenneth R.; Cheng, Cheng-Wei; Knapp, Ralf; Zhou, Lin; Lu, Ngan Thi; Zhou, Xin-Mao; Wei, Hong-Jin; Fan, Qiang; Chen, Su-Fang; Cicuzza, Daniele; Gao, Xin-Fen; Li, Wen-Bo; Zhang, Li-Bing (2020). "A global plastid phylogeny of the fern genus Asplenium (Aspleniaceae)". Cladistics. 36 (1): 22–71. doi:10.1111/cla.12384. PMID 34618950. S2CID 201197385.
- Media related to Asplenium nidus at Wikimedia Commons
- Data related to Asplenium nidus at Wikispecies
- Asplenium section - Flora Malesiana Symposium Abstracts