The first time I saw bird’s nest fungus, I couldn’t believe my eyes.
Here was a replica of a tiny bird’s nest, dollhouse-sized, with miniscule “eggs” inside it. The whole thing was less than a quarter of an inch across, and it was attached, along with several other little “nests,” to a piece of rotting wood.
Bird’s nest fungi are distant relatives of our familiar supermarket (portabello) mushrooms, and they grow in moist locations in woods, yards and gardens. However, they often go unnoticed because of their small size. Also, much of the time, they’re growing inconspicuously as a network of threadlike filaments (hyphae) within decaying wood, bark mulch and other moist substrates.
Like other fungi, bird’s nest fungi lack chlorophyll and don’t produce their own food by photosynthesis. They also don’t produce flowers, seeds or fruits.
But when environmental conditions are right, commonly in the spring or fall, bird’s nest fungi form their distinctive, cup-like reproductive structures, each holding several “eggs,” or peridioles. Each peridiole, in turn, contains numerous tiny spores.
The nest container itself functions as a “splash cup,” catching raindrops (or water from your sprinkler system). A splash of water into the cup can propel its peridioles three to four feet away — an astonishing distance considering how tiny all these fungal structures are. In many species of bird’s nest fungi, each peridiole has a long, sticky cord that adheres to, or wraps around, whatever it encounters during its watery flight.
The outer wall of the peridiole then breaks down, releasing the spores. If they’ve landed in a favorable habitat, the spores grow into more threadlike hyphae, thus continuing the life- cycle.
Bird’s nest fungi aren’t parasitic, nor do they cause plant disease. Although they’re reportedly inedible, none are said to be poisonous. Like many other fungi, they feed by decomposing organic matter within dead wood and mulch.
In the process, bird’s nest fungi perform an important ecological role by re-cycling nutrients and making them available to the roots of green plants.