Bird's Nest Fungi

What are they

Bird's nest fungi are a small group of saprophytic fungi that have a unique way of reproducing. They belong to the family Nidulariaceae until recently, but now have been moved into the Agaricaceae with the most common genera found in New Zealand being Nidula, Cyathus and Crucibulum.

What they look like

As their common name suggests, they look like small bird's nests, complete with eggs. In fact, the nest is a splash cup which is light to dark brown or white on the outside and white, grey or brown on the inside, depending on species. With smooth flaring sides between 4 and 10 mm in diameter and 6 to 20 mm in height, depending on species, the Immature Bird Nest has a cap over the top of the splash cup to protect the eggs, which break away at maturity. The eggs are small capsules known as peridioles which, contain the spores. These peridioles are lens shaped and shiny white, black-grey or dark brown.

Cyathus striatus

Where they grow

As bird's nest fungi are saprophytes and thus decomposers of organic material, they are found most often in New Zealand on decaying wood, small twigs, tree fern debris and sometimes on animal dung. In urban environments, they are often found in sawdust, wood chip, or well enriched soil, and landscaping timber. They do no harm to living plants.

Crucibulum laeve

How they work

The Bird’s Nest fungi use the hydraulic pressure of water to disperse their peridioles. This is achieved by rainwater or water dripping off foliage above, dripping into the splash cup. This cup is the right shape and size so that when the water hits the bottom of the cup, it splashes out with enough force to disperse the peridioles up to a meter away. When the peridioles land on a solid object, like a leaf or twig, they stick to it in one of two ways, depending on the species. The genera Nidularia and Nidula have sticky peridioles, while those in the genera Cyathus and Crucibulum have a coiled cord with a sticky end, which is attached to the splash cup. When the peridiole is splashed out, the end of the coil snaps and gives the peridiole a 100 mm tail which catches on any stem or twig in its path and wraps the peridiole around it.

Nidula niveo-tomentosa