Coniocarpon cinnabarinum DC.
Lamarck & de Candolle, Fl. franç., Edn 3 (Paris) 2: 323 (1805)
Previously : Arthonia tumidula (Ach.) Ach.
Neues J. Bot. 1(3. Stück): 11 (1806)
Basionym : Spiloma tumidulum Ach. 1803
White to pale gray, rarely pale red, sometimes with greenish tinge, effuse, often disrupting bark tissue, ±smooth, often bordered by red-brown prothalline lines; thallus in section up to 70 µm thick photobiont: Trentepohlia; cells: globose to ellipsoid, 8-15 x 4-12 µm, in short chains
Lower Side :
Ascomata: scattered to crowded, developed in outermost bark layers, soon erumpent and sessile, ±round, not distinctly branched, 0.12-0.5 mm wide, in section 100-150 µm thick disc: below the pruina fox-brown to almost hyaline, flat to convex, often densely covered by reddish or white pruina (if with white pruinose, then reddish pruina restricted to the periphery); below the ascomatal flanks often with dark violaceous, non-crystallized pigment; peripheric hyphal structures: composed of well differenciated, branched and anastomosing hyphae, with cells: 5-7 x 2-4 µm, with chestnut brown tinged outer cell walls; often incrusted by orange red grains epihymenium: ±interspersed with orange red grains and/or hyaline rhombic crystals, 10-20 µm thick; hyphae anastomosing and especially in outer parts branched and interlocking, outer cell walls hyaline (occasionally, when densely pruinose) to brown (often or when pruina reduced); cells 4-6 x 1.5-2 µm hymenium: hyaline to pale yellow, 60-100 µm tall, with closely spaced asci; paraphysoids: well developed and distinct in young ascomata, occasionally collapsed in mature ascomata, branched and anastomosing (especially above the asci), hyphae slightly sinuouse, irregularly thick; cells: 3-8 x 0.5-1 µm; subhymenium: hyaline to yellowish or pale reddish brown, 25-50 µm thick; cells irregularly ±round, 2-5 µm in diam., often without plasmatic content and ±collapsed; pigments amorphous, in and between the cell walls
Asci: clavate to broadly clavate, 60-80 x 20-25 µm, lateral walls ±thin, base not very distinct, 8-spored ascospores: initially hyaline but becoming externally brown, 4-7 septate (not incised at the septa), septation proceeding from the upper third downwards, oblong ovoid, 20-33 x 5.5-11 µm Pycnidia: very rare, ±round, 110-130 µm in diam. conidia: hyaline, non-septate, bacilliform, 4-6 x 1-1.5 µm
Ascomatal gels I+ blue; walls of thallus hyphae I+ pale blue; ascomatal gels KI+ blue; reddish pigments of epihymenium K+ red violet and dissolving; asci without KI+ blue thallus structures