Protologue type data: Type: Portugal, Madeira archipelago, Porto Santo, Pico do Castelo, 33°05'N, 16°20'W, 350 m alt., on sunexposed rock, 7 April 1988, R. Haugan et al. 6126 (O, holotype; BM and UPS, isotypes).

Type locality: Portugal, Madeira Islands, Porto Santo, Pico do Castelo, on sunexposed rock, 350 m, 7 April 1988, R. Haugan et al. 6126 (O - holotype; BM, UPS - isotypes)

Type locality coordinates: 33°05'N, 16°20'W.

ITS barcode: Data lacking.

Description: Lichen. Thallus foliose, adnate to loosely attached, orbicular, forming large rosettes up to c. 30 cm diam., pale grey, turning darker in older parts, without isidia and soredia; old specimens dying towards the center of the thallus. Lobes 1-2 mm wide, richly dichotomously branched, imbricate, broader and rounded towards the tips; older parts rugose, convex, richly pitted, with apothecia initials in the pits, smooth and flat towards the tips; lobe tips pruinose (calcium oxalate), faintly maculate. Medulla with a chondroid axis which is more or less discontinuous, being better developed above the rhizines than inbetween. Lower side with a continuous spongiostratum (frequently grazed by arthropods or snails, and therefore scattered towards the center), hardly visible from above, with a corticate outer surface when young. Rhizines developing from the chondroid axis, stout, black, sometimes weakly branched near the apex, rather scattered. Apothecia common, to c. 10 mm diam., pedicellate, cupuliform; disc scabrous, somewhat shining when young, red-brown to black; margin entire, thin, crenate when old; the thalline exciple finely tomentose, white to yellowish. Hymenium up to 125 µm deep, colorless, with an olivaceous brown pigment in the epithecium. Asci with numerous, crescent-shaped spores, 9-15 x 2-4 µm. Pycindia unknown (Haugan 1992: 46).

. Photobiont: Trebouxioid green alga.

Chemistry: Atranorin, divaricatic acid and several unknown terpenoids present: upper cortex K+ yellow (atranorin), C-, PD-, with crystals of unknown substance which are insoluble in acetone but soluble in KOH; medulla K-, C-, PD-, packed with crystals which extend into the rhizines (soluble in acetone and KOH); medulla outside the chondroid axis containing crystals of divaricatic acid (soluble in acetone and KOH); the transition zone between medulla and spongiostratum with crystals of calcium oxalate which are masked by other substances unless the section is treated with KOH; the inner zone of the spongiostratum (near the medulla) contains crystals (soluble in acetone and KOH); the thalline exciple of the apothecia K+ yellow, with an outer zone characterized by the same crystals as in the upper cortex, and an inner zone with crystals similar to those in the medulla; crystals of calcium oxalate are extending from the medulla inter the pedicels of the apothecia (Haugan 1992: 46).

Ecology: Saxicolous, on bare rock in a dry, sunexposed habitat, associated with e.g. Heterodermia leucomelos (L.) Poelt and Ramalina spp.

Distribution type: The species is known only from two localities on the volcanic neck Pico do Castelo on the island Porto Santo of the Madeira Islands.

Taxonomy: See Haugan (1992).

Note:

Distribution Database: Distributions

Distribution Database: Discover Life

Picture Database: Tropical Lichens

Molecular Database: Genbank

Synonym Database: Index Fungorum

Synonym Database: Mycobank