Click on map to open large map in new window
(Map updated: 11 August 2009)

This elm-tree specialist forms dark, olive green to grey, mealy-granular patches covered with purplish-brown to black, flattish discs on tree sap weeps or on hollowing out bark. Colonies of this species have been devastated by Dutch elm disease and whereas it was once recorded (post 1960) from several southern and south-western counties, it is now presumed to be extinct. In Ireland, the species has also been recorded from holly, sycamore and beech. The species may be surviving in out-of-the-way places so is worth searching for.

Key characteristics

• On wound tracks of elm and other trees
• The mealy-granular, olive green thallus and purplish-brown discs with a dark internal pigmentation distinguishes it.

Original text submitted by Vince J. Giavarini