The presence of persistent, brown-to-black spots on cars, house siding, plants, and other surfaces may be an indication of the presence of the fungus Sphaerobolus stellatus — artillery fungus. These brown spots are the spore dispersal structures of this fungus. Spore masses should be removed from affected surfaces with a stiff water spray from a hose or by scrubbing with a wet cloth or stiff brush before they dry. Unfortunately, in most cases this is not practical and removal is usually attempted after the spores have dried. When this is the case, they are very difficult to remove and must be physically scrubbed and scraped from the affected surfaces. Before attempting to remove these fungal spores from siding, car finishes or other valuables, test a small surface area to be sure there will be no damage.