Crucibulum laeve

Description

Crucibuum laevae is distinguished by a buff-brown, thin-walled, flaring cup with a smooth interior, and pallid to white eggs that are connected to the cup via a thin cord.

This mushroom is one of several species of bird's-nest fungi and is among the most common. That's not to say that any of the bird's-nest fungi are easy to find, as they are so tiny and easily overlooked. This remarkable fungus grows on rotting wood (commonly small twigs) and dead stems of other vegetation.

The cord, which is called a "funiculus" in Mycologese, is the egg's mechanism for attaching itself to sticks, leaves, and other plant debris. When a raindrop falls into the nest, the eggs are projected out of the cup. As this happens, the cord is stretched to its limit - then breaks away from the nest, remaining attached to the egg. Where the cord was attached to the nest, it becomes frayed, since it was torn away. The little frayed ends are adhesive, and when they come into contact with, for example, a leaf, they attach themselves. This stops the flight of the egg, which then swings back and attaches itself to the leaf as well.

Common names: Bird's Nest Fungus.

Mushroom Identification

1. Sporocarp

   Fruiting body cup-shaped, sessile, tough, persistent, 3-7 mm high, 3-6 mm wide, globose, becoming cylindrical, narrowed at the base, flaring at the mouth, the latter covered with an ochraceous, velvety, evanescent lid (epiphragm); outer surface roughened to finely wrinkled, buff-brown, inner surface smooth, pale grey to light-brown; peridioles (eggs) 1-2 mm broad, flattened, white to pallid, connected to the cup by a thin cord (funiculus).

2. Spores

   Spores 7.5-10 x 4-6 µm, elliptical, smooth, nonamyloid.

3. Habitat

   Scattered to clustered on soil and woody debris, e.g. sticks, rotting plywood, etc.

4. Similar Species

   The Cyathus olla, which is larger.

History

This gasteromycete fungus was described in 1778 by the British mycologist William Hudson (1730 - 1793), who gave it the binomial scientific name Peziza laevis.

It was American mycologist P E Kambly who in 1936 transferred this species to the genus Crucibulum, whereupon it acquired its currently accepted scientific name Crucibulum laeve.

Synonyms of Crucibulum laeve include Peziza crucibuliformis Schaeff., Peziza laevis Huds., Peziza lentifera Huds., Cyathus crucibuliformis (Schaeff.) Hoffm., Nidularia laevis (Huds.) Huds., Cyathus scutellaris Roth, Cyathus crucibulum Pers., Nidularia crucibulum Fr., and Crucibulum vulgare Tul. & C. Tul.

The generic name Crucibulum means in the form of a crucible, while the specific epithet laeve means smooth - a reference to the smooth inner surfaces of the 'nests'.

Photo sources:

Photo 1 - Author: Gilles San Martin (CC BY-SA 2.0)

Photo 2 - Author: Alexis (CC BY-SA 4.0)

Photo 3 - Author: Richard Jacob (CC BY-SA 4.0)

Photo 4 - Author: Christian Grenier (Public Domain)