I think they might be one of these or something similar:
http://mushroomexpert.com/leucocoprinus_birnbaumii.html
Yeah that's what I found too....my site said to leave them alone and enjoy them
Oh and you should appreciate that they were 2002 February Fungus of the Month
Tom Volk's Fungus of the Month for February 2002This month's fungus is Leucocoprinus birnbaumii, aka Lepiota lutea, the yellow houseplant mushroom.
For the rest of my pages on fungi, please click
http://TomVolkFungi.net Leucocoprinus birnbaumii (luke-o-kuh-PRY-niss burn-BAUM-eee-eye) is a common mushroom in house plants and greenhouses or any other place with organically rich soil where the temperature is warm . I get lots of emails about this particular fungus in the winter, so I thought that it's about time to make it the Fungus of the Month. It's a bright colorful mushroom that helps those of us in the far north get through the long, mostly mushroomlesss winter. It's also very common in the south in warmer climates, where it can grow outdoors, especially in mulched flower beds.
I get *lots* of email about this fungus. In the table below I've put a small sampling of some of these interesting emails. You'll notice, however, that they start to sound the same after the first few. That's why I made Leucocoprinus birnbaum