Graphis furcata
A quite distinctive pan-tropical Graphis species, recently identified from a 19th century herbarium specimen collected in Meirionnydd, North Wales. The lirelllae are slender (to 0.2 mm wide) with entirely closed and non-inspersed hymenia and the thallus is partly ecorticate. Should be looked for in oceanic woods.
Similar to Graphis scripta s. lat., but the ascomata are slender (to 0.2 mm wide) with entirely closed and non-inspersed hymenia and the thallus is partly ecorticate. Ascospores ca 20 × 6 µm, 7-septate (25–35 × 7–10 μm, 5–9-septate fide Lücking et al. 2009). Hamathecium not inspersed with oil droplets.
Found before 1892 on bark of an unidentified tree in Dolgellau (VC 48) but only recently recognised as British. The species appears to have a very broad, primarily tropical distribution, and may include morphological lookalikes. A South African specimen was illustrated by Medeiros & Lutzoni (2022), and one from the Azores by Van den Boom et al. (2023).
Epiphytic, with the only British record from an area with a temperate rainforest climate
There is a 19th century record from Meirionnydd. Should be looked for there and in other oceanic areas.
No recent record but potentially over looked but even so likely to be rare, so best regarded as Data Deficient
Aptroot, A., Weerakoon, G., Cannon, P., Coppins, B., Sanderson, N. & Simkin, J. (2023). Ostropales: Graphidaceae, including the genera Allographa, Clandestinotrema, Crutarndina, Diploschistes, Fissurina, Graphis, Leucodecton, Phaeographis, Schizotrema, Thelotrema and Topeliopsis. Revisions of British and Irish Lichens 36: 1-23.
Medeiros, I.D. & Lutzoni, F. (2022). Contribution to a modern treatment of Graphidaceae biodiversity in South Africa: genera of tribe Graphideae with hyaline ascospores. Lichenologist 54: 253–270
Van den Boom, P.P.G., Lücking, R. & Sipman, H.J.M. (2023). Notes on Graphidaceae in Macaronesia, with descriptions of four new species. Diversity 15: 817.
Text by Neil A Sanderson based on Aptroot et al (2023)