This webcap mushroom- believed to be Cortinarius ochroleucus– has recently been found growing at the Botanics. The fungus, which is a new record for Edinburgh (Vice County 83), was found growing under a mature American chestnut tree on RBGE’s west border.
Cortinarius mushrooms, commonly known as webcaps, are the largest genus of mushrooms in the world, comprising of over 1000 species. The webcaps get their name from the partial veil covering the gills of the young mushroom. As the mushroom matures, this veil stretches and tears, leaving a cobwebby ring around the stem. This ring, or cortina, then becomes dusted with rusty brown spores, making it more discernable. All webcaps are mycorrhizal, meaning that they form mutually beneficial relationships with trees.
C.ochroleucus is part of the subgenus Myxacium- the members of which are characterised by a slimy cap and stem. This particular webcap stands out from the crowd because of its white- grey colouring. The white sheen can be rubbed off with a finger revealing the ochre brown flesh below- hence the specific name ochroleucus– “ochre white”.