|Last year, I had a problem with some sort of fungus growing (and spreading) across my mulched flower beds. It first appeared looking like someone had spilled bright yellow paint on the woodchips. After several days, the color dulled, but the "paint" puffed up, looking like an off-white, congealed popcorn. In that stage, whenever it was touched, by hand or by water, it would release clouds of black spores. I found it difficult to remove without causing it to spread further. What is it, how do I prevent it, and once I have it, how do I remove it or kill it?