Cannon Fungus: Sphaerobolus stellatus

Sporocarp
Fruiting body globose, in age, cup-shaped, 2-3 mm broad, usually erumpent from a lignicolous substrate, occasionally developing from a pallid, surface mycelial layer; outer cup surface (peridial layer) cream-buff to ochraceous, matted tomentose, pliant, soon splitting, forming 5-7 short lobes; inner-most peridial layer translucent, tinged yellow, surrounding a glebal mass (peridiole), at maturity suddenly everting, ejecting a dark-brown, sticky peridiole; remnants of the inner peridial layer, inflated, balloon-like, briefly remaining attached to the lobe tips; in age the cups whitish and empty.

Spores

Habitat
Clustered on standing dead wood, fallen logs, and woody debris; fruiting throughout the mushroom season.

Edibility
Unknown. Far too small to be of culinary value.

Comments
This tiny gasteromycete is known for its cannon-like ability to eject a spore mass (peridiole) a considerable distance, sometimes many feet. Though rarely seen because of its size, it is probably common and there are reports of it fruiting in sufficiently large numbers in mulched plantings to cause problems for homeowners, masses of the pinhead-sized, dark peridioles adhering to the paint surfaces of cars and buildings. Do not confuse the inflated, translucent inner peridium, often seen on the cup lobes for the gleba mass (peridiole). The "balloon" indicates that the peridiole has already been shot off.