jcn,
They're not a problem.
The spores probably came in w/ that wood mulch.

Actually it means your soil is healthy and contains a nice balance of mico-organisms.

We get them every year and they will be gone in a few days.

Ric

Yeah as Ric noted, they are just the 'shrooms from spores that were in the soil and mulch and now they now have the right conditions to pop up and grow.

I had stuff like that coming up in almost ALL my containers last summer after all the rain and overcast we had then. I had this lovely specimen pop up in my passiflora edulis container last year:

{{gwi:2903}}

And then they multiplied... LOL

{{gwi:2904}}

And as you note, your area has had ALOT of rain. I've had orange ones, yellow ones like yours with that narrow profile, white ones, gray ones, you name it. Soon as it dries out, the air dries up, and the sun comes out for more than a day or two, they dry up and decompose and add nutrients to the soil.