Here the crustlike fruiting or reproductive state is formed, which is the only stage that most of us ever see. They are filled with dark masses of powdery spores that are easily rubbed off the leaf or stem. Click on image for larger version Figure 2. Click on image for larger version Figure 3. Slime mold growing on sundial near blueberries.
Slime molds are nonparasitic.
They are much more unsightly than harmful and merely use grass leaves and stems as a means of support for their reproductive structures. Slight damage may occur when leaves are smothered or shaded for several days to a week. The weakened and somewhat yellow grass leaves are more susceptible to killing by secondary fungi and bacteria. An abundance of straw mulch favors slime molds by providing a ready source of organic matter and high populations of microorganisms. No control measures are usually considered necessary.