Cortinarius lacustris

A medium to large sized webcap which occurs in deciduous woodland, frequently in conspicuous troops under oak. It belongs to the Cortinarius hinnuleus complex of webcaps and is probably the one that is most commonly reprsented in West Glamorgan. It has the typical, sharply umbonate cap of Cortinarius hinnuleus but the yellowish or tawny colour of the cap is quite distinctive. A drop of KOH on the the flesh at the base of the stem quickly produces a dark-violet or balck reaction.