Thanks, when I first looked at your image I incorrectly assumed the fungus was growing in an old pot with dead plant remnants. Laccaria as it is currently known is regarded as a genus of obligatory ectomycorrhizal fungi, so only found in association with the roots of living plants. A fairly technical reference for this is Wilson et al. in the journal New Phytologist (2017) 213: 1862–1873. The paper is open access.