The bird’s-nest fern (Asplenium nidus) is a large, leafy fern commonly found on wayside trees in Singapore, particularly the rain tree.1 The fern, which grows at the base of large branches, has a unique ability to trap water and develop its own store of humus.

Description
The bird’s-nest fern is an epiphyte plant that can be found in Asia, Australia, and Africa.2 It has a stout erect rhizome (stem) that bears a rosette of simple leaves (fronds) to form a “nest”. The stem is usually not visible from the top. Beneath the nest of fronds is a large, spongy mass of roots.

The nest traps fallen leaves and other debris, which eventually decompose to become humus. When it rains, large quantities of water are absorbed by the sponge of roots.3 In this way, the plant is self-sufficient in acquiring its food and water, so much so that it provides a habitat for the growth of other ferns and mosses, and even home for small animals.4

The fronds can grow to a length of more than a metre and a width of about 20 cm, with the whole plant extending about two metres across.5 The leaves are in a shiny light-green colour, with a smooth, sometimes wavy-edged, blade as well as a prominent black midrib. The sporangia – sacs that produce spores for reproduction – are found on the underside of the fronds in parallel rows inclined at 45 deg to the midrib. The fern produces plentiful spores that are dispersed by wind.

In some Malay rural areas, the plant is believed to have supernatural properties, or the home of the langsuir, a mythical female banshee hostile to pregnant women.

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