Key Features
- Black, flattened seed-like structures
- On mulched plants
- Unsightly but not a disease
Symptoms
Black spots, like flattened poppy seeds, stick to leaves, stems, and any other nearby material. There is often webbing associated with the spots. It may be mistaken for a disease or insect problem. In the case of birds nest fungi, the cup-like "nest" holds tiny "eggs" (called periodoles), which are little spore sacs. Periodoles are dispersed by raindrops. For artillery fungi, when it matures, the spore mass (called a gleba) reaches about 1mm in diameter suspended in liquid in the cup until it is catapulted into the air with enough force to project it up to 20 feet. Upon contact, the sticky coating adheres to whatever it hits. Its ability to adhere to surfaces is the stuff of legends.
Biology
Fungi emerge as club-like structures in mulch. They are often numerous. As they develop, dry "eggs" peridioles are visible in the "nest". This is different than the gelatinous spore mass that forms in the cup of an artillery fungus. After discharge of spores, an empty cup often remains in the mulch.
Management Recommendations
Artillery fungi grow on mulched landscape wood as opposed to bark and grow best on mulch sited on the north side of a structures where it is cooler and wetter. Mushroom compost has been shown to suppress artillery fungus fruit body production. No fungicides are labeled for control of this problem.
Effective Pesticides
Pesticides are neither available nor recommended for managing this disease.
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
