I did a Seek on the photo it says Mottle gill mushroom mate.
See what you think of it on the Wildwood.com site link mate.
To be honest I would not encourage the fungi in household plants. But still interesting.
Brown Mottlegill
WWW.WILDFOODUK.COM
Brown Mottlegill, Panaeolina foenisecii, Panaeolus foenisecii, LBM, Inedible, Grassland mushroom, Saprotrophic mushroom
Cheers Arry