Arctomia

Small crust-like lichens containing cyanobacteria (Nostoc), gelatinized throughout the thallus, giving a translucency when wet; apothecia dome-shaped, red-brown, with a thin exciple, lacking a thalline rim; paraphyses mostly straight and unbranched, embedded in thick, K- gel, the upper portions of the hymenium with a brown pigment that persists in K; asci clavate, IKI+ blue; spores 8 per ascus, colourless, bacilliform, with multiple transverse septae.

References: Jørgensen 2007.

Thallus gelatinous, usually a mass of indistinctly shaped granules or squamules; apothecia dark brownish red, with a thin, quickly receding proper exciple; paraphyses brown-pigmented, unbranched, often somewhat swollen at the tip; asci broadly cylindrical, bearing 8 spores; spores colorless, 6- to 13-septate, 40-80 × 4-5.5  µ; to be sought …[Arctomia delicatula Th. Fr.]