Main photograph courtesy: Leif Goodwin [sometimes called G. purpuratus incorrectly]. Beautiful photo ! Suprised to see it with oak though (noted the acorns !!) since usually on piles of woodchips, mostly in garden type locations. (ref: Nick Legon) A beautiful toadstool which is bright purple when young, (resembling Tricholompsis rutilans but with a ring), rapidly fading to orange-brown. Originally from South East Asia where it grows on old coconut stumps, it was possibly introduced with coir imported for horticultural use as a peat replacement. It is one of a number of recent introductions and colonists which grow on wood chips. It is becoming more common and widespread in this habitat, but requires warmth so is restricted to large piles of chips which are heating up through fermention, or indoors in pots with house plants. (ref: BioImages UK)