Sphaerobolus

thumb|Sphaerobolus sp. on Elwha Watershed, WA USA

Sphaerobolus is a genus of fungi in the family Geastraceae. Commonly known as the "shotgun fungus", "artillery fungus" or "cannonball fungus", species discharge their spores with explosive force. Discharged spore sacs are sticky and have a tendency to strongly adhere to whatever surface they encounter, making them a nuisance to homeowners, pressure washing contractors, landscape mulch producers and insurance companies.