Pencilmark lichen

Crustose lichen.

Very variable. Smooth or wrinkled white or grey thallus with curved or forked apothecia (lirellae). Centres of lirellae open, white pruinose. Similar to G. elegans but carbonaceous margins are raised and unfurrowed.
Mature spores are colourless but may become brown when old.

Widespread and often common on smooth bark. Generally the commonest of a group of very similar species, including species of Graphina and Phaeographis, that require microscopic examination for certain identification.One of the main species of the Graphidion lichen community found on smooth hazel stems.

Sometimes parasitised by Stigmidium microspilum