Asplenium australasicum

bird's nest fern


Asplenium australasicum

(J.Sm.) Hook. 1854

pronounced: ass-PLEE-nee-um aw-strah-LAY-see-kum

(Aspleniaceae — the spleenwort family)

also known as — Asplenium nidus

L. 1753

pronounced: ass-PLEE-nee-um NID-uss

common names: bird's nest fern, crow's nest fern

native 4Asplenium is from the Greek ασπληνος (asplenos), literally, ‘without spleen’, the spleenwort, allegedly a curative of spleen problems, named by Pliny and Dioscorides and taken by Linnaeus to be Asplenium ceterach; australasicum is botanical Latin for ‘of/from Australasia’. Nidus is Latin for ‘nest’.

I am pretty certain that the plant pictured is Asplenium australasicum, rather than Asplenium nidus, but it is difficult to be sure, as they are very similar. The latter is seldom grown under cultivation, but many nurseries will sell you the former under the latter name, usually through ignorance rather than through a wish to deceive. Asplenium australasicum is a useful plant for shady areas. Being naturally an epiphyte or a lithophyte from the rainforest, it’s ideal for growing under trees where few other plants can compete with tree roots. Its dramatic form works well with a modern garden style as well as a more naturalistic rainforest garden.

The fern is found in Queensland, NSW to the south coast, and Asia. In southern Queensland and NSW the fern is generally larger than in northern Queensland, and there are suggestions than this smaller fern may be a distinct genetic race. The fern is well-adapted to the sometimes harsh conditions of the rainforest, and recovers quickly with the assistance of rain even though the leaves may look wilted, brown and beyond repair.

Fronds are yellow-green to green, simple, erect and arranged in a rosette; they have a distinct raised midrib below. The tip mat be blunt or pointed. Fronds can reach 2 m long and 20 cm wide, but in North Queensland fronds usually grow less than one metre long. The nest-shaped radiating fronds catch dead leaves and other rainforest litter, caught as the leaves bend outwards with age. This litter rots down and forms a growing medium for the root system of the fern, and also for other nearby epiphytes. The root system is small, considering the size of the fern, but it is dense and spongy, and is covered with persistent brown root hairs.

Because of its small root system, it is excellent for growing in a pot, tub or basket, but it is also suitable for growing in the ground. It dislikes being in full shade or wet soil, and prefers filtered sunlight and a dry situation, such as under the eaves of the house or under a large gum tree. There are many of these ferns growing in island gardens.

The fern is propagated by spores. These are produced by structures called sporangia. The sporangia are aggregated on the back of the fronds in groups known as sori.These are arranged about 4 mm apart in a straight line from the mid-rib and cover about ¾ of the width of the frond.

Asplenium nidus, the species with which this is often confused, occurs on Cape York and through New Guinea, tropical South-east Asia, and as far as Tahiti and Hawaii.


Photographs taken in Picnic Bay 2010
Page last updated 14th October 2018