We had new tanbark laid down in our backyard and have been finding black tar looking patches after it rains. We clean them up...then it rains and new patches of it show up again. Have you seen this before or have any idea what it is?
Three more patches of the stuff this morning after last nights rain. I've sent pictures and also have saved the globs should you need them to help with identification.
This is a slime mold. These organisms exist in nature as a “blob” (plasmodium), similar to an amoeba. And they engulf their food, mostly bacteria. The slime mold that typically appear on mulches are from the genus, Fuligo.
They tend to appear and disappear equally quickly. They are a curiosity more than anything to worry about. See a short discussion of slime molds from the PNW Disease Management Handbook.
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