I recently found what I think are fungi in the growing medium in a 30 cm pot that contains an epiphyllum 'orchid' (cactus). There are several that appear new and more that look old or are decaying. I've included a picture with the fruiting body on the left - the coin is 1.8 cm in diameter and the small round ball is Osmocote.

The fruiting feels 'woody' when I touch it and is close to or touching the soil surface. I let the soil get kind of dry between waterings and I'm in Southern California where it is hot. The soil surface gets no direct sun. I've not repotted the plant but the soil is well draining and appears to have woody material in it.

I realize that it is unlikely that it will be identified to species but I'd like to know a bit about it.