Arthonia sampaianae
An obligate parasite of Nevesia sampaiana confined to the temperate rainforest of the western Highlands, in well developed old growth stands that support large populations of the host. The apothecia are immersed in galls on the host thallus.
Thallus absent, lichenicolous on Nevesia sampaiana. Apothecia single or in groups of 2–5, 0.2–0.5 mm diam., immersed in galls 0.5–1 mm diam., dark brown to black, rounded, flat; epithecium brown, K+ olive; hymenium 100–140 μm tall, brownish, K+ olive, I+ red; hypothecium colourless; paraphysoids 2–4 μm diam., the apices pigmented but not enlarged. Asci clavate, 4- to 8-spored, 60–90 × 17–21 μm. Ascospores 20–26 × 6–8 μm, 3-septate, colourless, with a 0.5–4 μm thick perispore which becomes dark brown at maturity, slightly contricted at the septa. Lichen substances unknown.
In galls on thallus of Nevesia sampaiana in temperate rainforest.
Rare, western Highlands, Scotland (Argyll & Westerness).
An obligate parasite of Nevesia sampaiana confined to the temperate rainforest of the western Highlands, in well developed old growth stands that support large populations of the host.
Britain: Near Threatened
Cannon, P., Ertz, D., Frisch, A., Aptroot, A., Chambers, S., Coppins, B. J., Sanderson, N. A., Simkin, J. & Wolseley, P. (2020) Revisions of British and Irish Lichens Volume 1 August 2020 Arthoniales: Arthoniaceae. BLS
Text by Neil A Sanderson, based on Cannon et al (2020)