Native Plants of Hawai‘i - Asplenium nidus

Asplenium nidus

(There is some controversy as to whether this species is native or naturalized. We hope to resolve this in the near future.)

Aspleniacaeae or Spleenwort family

Synonyms: Neottopteris nidus, Tarachia polyphylla

ʻĒkaha

ʻĀkaha, ʻĒkaha kuahiwi

Bird's-nest fern

Natural Range & Environment

Asplenium nidus is a relatively common indigenous fern found on Kauaʻi, Oʻahu, Lānaʻi, Molokaʻi, Maui, and Hawaiʻi Island, 40-762 m (ca. 130-2,500 ft) as an epiphyte in lateral branches or crotches (bases) of large native (e.g., ʻahakea, koa) and non-native (monkey pod) tree branches, as a lithophyte (on rocks), and occasionally as a terrestrial [Palmer 2003]. A. nidus is also native to Malesia and Southeast Asia [Thomas 2025].

Nice examples of cultivated ʻēkaha on an Oʻahu college campus and in a botanical garden growing with another indigenous fern, kupukupu (Nephrolepis cordifolia). The very wide leaves and sori arrangement leave no doubt that this is indeed Asplenium nidus. Growing as an epiphyte in leaf debris with moa nahele (Psilotum complanatum) in the crotch of a huge ʻahakea (Bobea elatior), an endemic tree in a mesic forest in the Koʻolau Mountains, Oʻahu.

Description

ʻĒkaha (Asplenium nidus) is one of the most recognizable of all ferns in the Hawaiian Islands. It is distinguished by its impressive, broad fronds that can reach lengths of 3 to 5 feet, resembling the shape and texture of banana (Musa spp.) leaves. A notable feature of this fern is the abundance of long, parallel rows of sori—clusters of fern spores—adorning the undersides of its fronds, which impart a unique, rusty appearance.

Growth Requirements

General

These vibrant yet relatively slow-growing ferns make excellent accent plants for shaded to partially sunny areas beneath trees. They thrive in pots and hanging baskets, particularly in shaded locations such as on a north- or east-facing lanaʻi. Additionally, these ferns can be cultivated as indoor container plants and are well-suited for bathrooms, where humidity levels are typically higher.

While ʻēkaha can tolerate some sunlight, excessive exposure may scorch their leaves, resulting in an unsightly appearance. Fortunately, they often recover, albeit slowly, especially if new growth (emerging fronds) remains unaffected and the plants are relocated to a shadier environment.

These ferns can be utilized in various ways: planted directly in the ground (terrestrial), nestled among rocks or in crevices (lithophyte), or positioned on tree branches or within branch crotches as epiphytes. Smaller ferns can be secured to branches using twine or nylon stockings and should be kept moist until they establish roots. For an aesthetically pleasing display, consider placing them among large boulders, allowing ample space for their fronds to flourish. Larger ʻēkaha require additional support, as they may topple in windy conditions if not properly anchored. See the following illustrations and explanations to ensure that your fern is anchored and stable in a garden.
For potted ʻēkaha, apply a slow-release 13-13-13 fertilizer every six months. If larger potted ferns exhibit poor coloration or fail to produce crosiers (fiddleheads or emerging fronds), consider using a complete fertilizer at half the recommended strength. Kay Lynch (Lāʻau Hawaiʻi) suggests that it is important not to till solid fertilizers into the soil, as ferns possess a shallow root system that can be easily disturbed.

Pests and Diseases

Scale and whiteflies can be problematic. Refer to the Pests & Diseases page for treatments.

Since ʻēkaha can be top-heavy until established, a tried and proven method to give it an epiphytic look in a garden is to counter-balance the fern by providing weight at the bottom. This example shows a 7½" x 7½" block with a one-inch pipe and filled with quick-drying concrete. The concrete block can be placed partly or fully buried in the ground for extra stability. This setup will provide the required support for a dead hollow hapuʻu stump, which can be filled with first cinder, then a mixture of soil or potting mix and debris such as leaf litter. To provide even greater stability and weight, a pipe can first be driven into the ground, and then the block and cement added. Leave room for the ʻēkaha to be planted at the top. With generous amounts of water and partial sun, it will soon become another natural feature in your garden. This is only one variation of many, and you can modify it for your needs.

Uses

Ancient Hawaiian

The dark midribs of ʻēkaha fronds were intricately woven into lau hala mats and various other lau hala objects, providing a striking contrast in both pattern and color. [Krauss 1993, Neal 1965]
D.M. Kaʻaiakamanu notes that a liquid derived from the leaf shoots of ʻēkaha, when combined with other plants, was traditionally used to treat children and infants suffering from ʻea (thrush) and pāʻaoʻao, a condition that causes physical weakness [Ka‘aiakamanu & Akina 1922]. Further, Kaʻaiakamanu says that the shoots were pounded together with other botanicals, and the resulting liquid was administered to children with mouth sores or general weakness. Additionally, an ointment made from the leaves, mixed with other ingredients, was applied to ulcers and body sores (known as pūhō kolokolo kokoʻole) [Ka‘aiakamanu & Akina 1922].
ʻĒkaha was ceremonially planted to conceal residual stumps after trees were felled for canoe (waʻa) construction, serving both a practical and symbolic purpose before the wood was shaped with an adze [Krauss 1993].

Modern
While ʻēkaha is a popular houseplant today, it is important to note that bird's-nest ferns sold in many garden shops in Hawaiʻi may not be from Hawaiʻi and, in fact, some are actually Asplenium australasicum, a similar species native to eastern New South Wales and Queensland, Australia. A bird's-nest fern with wavy edges is your first clue that it is likely the non-native A. australasicum. This underscores the importance of sourcing true ʻēkaha (Asplenium nidus) from reputable native plant suppliers, such as those found in Where can you buy these plants? on this website.

Special Features and Information

General

ʻĒkaha (Asplenium nidus) belongs to one of the largest fern families, Apleniaceae or the Spleenwort family. There are 26 species of Asplenium ferns native to the Hawaiian Islands, 16 of which are endemic [Flora of the Hawaiian Islands].

On Oʻahu (southern Koʻolau Mts.) and Maui in dry to mesic forests, very young ʻēkaha, known as ʻēkahakaha, are frequently seen with another indigenous fern, ʻoheʻohe (Haplopteris elongata). The long, narrow fronds and rhizomes of ʻoheʻohe appear to look like aerial roots coming from the accompanying ʻēkaha. It is not clear if ʻoheʻohe is growing as an epiphyte on ʻēkaha or the reverse. There may be a mutual advantage [Palmer 2003].

Hawaiian Name

This fern is sometimes called ʻēkaha kuahiwi, meaning "mountain ʻēkaha," to distinguish it from the mosses or from ʻēkaha kū moana (black coral) [Hawaiian Dictionaries]. ʻĒkahakaha is a juvenile form of ʻēkaha [Palmer 2003]. ʻĀkaha is the same as ʻĒkaha [Hawaiian Dictionaries].

Etymology

The generic name Asplenium is from the Latin asplenum, meaning "spleenwort." Ancient Greeks believed that this fern could cure spleen diseases [Thomas et al. 2025].

The specific epithet nidus, nest or nest-like [Gledhill 2008].

DWE