Wow those sure are fascinating! I have no recommendations for you. But I did just want to say that is one good looking Norfolk pine and the Ficus Audrey next to it sure is pretty as well! Seems like they like you and that spot!

Thank you, popmama. I'm lucky to have a very large picture window with southern (slightly obstructed) exposure. Many of my plants live there or rotate through.

That's such a common mushroom (fungus) in typical peat based potting mixes that it has a nickname: yellow potting soil mushroom. Miracle-Gro® is one of the worst products as far as being consistently contaminated with these fungal spores, but any peat based product can develop an outcropping of the little yellow shrooms.

Gardengal is right that the fungus is simply feeding on the organic matter in the potting medium and won't harm your plant. In the long run, however, your nice, coarse potting mix will be decomposed to a muckier product.

Look it up under the nick name or the scientific binomial, Leucocoprinus birnbaumii, if you're interested in learning more.

Just remove the mushrooms as you see them. They will release lots of spores when they mature which in a few days their life span will be over. As others have said they are not harmful but they can be unsightly when they decompose themselves.

Thanks, folks. I'm glad to know I needn't rush to repot.

By the way, the mushrooms are the minor part of the fungal body, simply the fruiting body. The working part of the fungus is a network of threadlike mycelium and hyphae which develop in the soil and work non-stop to decompose and feed on the organic matter.

You can certainly remove the yellow mushrooms, but the true decomposing part will remain hard at work until you eventually repot.

Thanks, rhizo, I realize that, but I'm still going to remove the fruiting body so it doesn't spread spores all over the place!