"Habitat: On soil (often calcareous) in deciduous woodland. Often associated with Quercus spp., but also reported with Fagus and Fraxinus. Notes: This is a small but distinctive species, possibly genuinely rare though widespread in Britain. Known from England (Bedfordshire, Berkshire, Herefordshire, Hertfordshire, Oxfordshire, Surrey, West Kent and West Sussex) and a single collection from Scotland (Easterness)." 

Conservation Status: Vulnerable (Red Data List, ed. 1); Near Threatened (Red Data List, ed. 2)
Ref: Checklist of British Basidiomycota

More info and a modified key supplied by Ken in forum Ref: http://tinyurl.com/4nl4by

Photograph copyright Leif Goodwin