Cobalt Crust - Terana caerulea

    Alt Name
    Pulcherricium caeruleum

    This corticioid (crust-like) fungus is a real beauty, especially when young and fresh with a bright cobalt blue appearance. The rounded fruit-bodies coalesce to form irregular large patches with either smooth or slightly bumpy or warty fertile surfaces that are usually finely velvety. This is a very thin crust fungus, generally much less than 1 mm thick. When moist, the texture of these crust fungi is quite soft with a waxy feel, and the outer margins are pale, sometimes whitish, and finely fringed. Old specimens turn dark blue and eventually almost black.

    Identification difficulty

    Found on dead hardwood trees and fallen branches, particularly Ash (Fraxinus excelsior).

    When to see it

    All year round.

    Life History


    UK Status

    Infrequent or occasional in England and Wales and very rarely recorded in Scotland and Ireland.

    VC55 Status

    Infrequent in Leicestershire and Rutland. The Barnsdale record of January 2017 is the 6th record for VC55.

    Leicestershire & Rutland Map

    MAP KEY:

    Yellow squares = NBN records (all known data)
    Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

    UK Map