Protoparmeliopsis muralis (Schreb.) M. Choisy | MYCO-LICH

Protoparmeliopsis muralis (Schreb.) M. Choisy

Synonymy : 
Lecanora albomarginata
Synonymy : 
Lecanora muralis
Synonymy : 
Squamaria albomarginata
Synonymy : 
Squamaria muralis
IUCN Threat Status: 
Not Evaluated

Thallus: placodioid, 1.5-3.5 cm or more wide, 0.5-2 mm or more thick in center, primarily forming neat rosettes, but often either confluent or +dispersed and irregular, tightly to loosely attached; areolate to squamulose; prothallus: absent or vestigial, with the outermost edges and especially the extreme lobe tips often darkened blue-green to black areoles: contiguous or +scattered, irregularly +round, 0.5-1 mm wide; edges: sometimes raised and thickened lobes: radiating to randomly oriented, contiguous to discrete, 1.5-4.5(-6) mm long, 0.5-0.6(-1.5) mm wide, sometimes short and squamule-like, plane, concave, convex, or undulate with the edges folded along sinuses, but not sinuous-plicate; edges: plane or raised and thickened especially towards tips; simple to incised-crenate, the ultimate segments 0.3-1 mm wide upper surface: grayish yellow green to pale greenish yellow, grayish yellow, more yellow towards the lobe tips (in herbarium becoming medium yellow to pale brown or orange; coastal forms: often very pale yellowish green), continuous to rimose, +shiny or waxy; usually pruinose on margins (especially folded sinuses), or +spotily pruinose on warty areas near lobe tips (v. versicolor), or entire surface becoming +densely pruinose (e.g., albopulverulenta), esorediate upper cortex: cone cortex type, without dead algal cells, 50-75 µm or more thick, inspersed with yellowish granules (soluble in K, insoluble in N); hyphae: randomly oriented to anticlinal, 3-5 µm in diam.; lumina: c. 2 µm wide; epinecral layer: 5-10(-15) µm thick medulla: solid but rather loose and cottony; algal layer: unevenly thickened and divided lower surface: white, or pale to deep yellow or brown, or at least partly blue-green to black lower cortex: mostly confined to areas near the tips or margins of the lobes, indistinct and poorly developed Apothecia: few to crowded towards thallus center, borne marginally or submarginally, one to several per areole, subimmersed then +broadly sessile, 0.8-1.8(-2.3) mm in diam. disc: often varying on the same thallus from light yellow to pale to dark yellow, orange- or red-brown or blackening or sometimes greenish gray near the margin, plane or sometimes convex, dull or shiny, epruinose margin: concolorous with thallus or pale yellow to pale orangish yellow, +raised then level with disc, 0.1-0.3 mm wide, dull or shiny, occasionally with thin white outer edge or thin black outer edge, sometimes +completely pruinose, entire to flexuous or crenate, finally excluded, often with a very distinct, +yellow to brown parathecial ring amphithecium: present, with an interrupted algal layer c. 50 µm thick located mostly next to the parathecium, sometimes with granules or a few coarse hyaline crystals (insoluble in K) in the medulla, corticate; cortex: similar in structure to that of thallus parathecium: hyaline, weakly differentiated from hypothecium, with conglutinated, thick-walled hyphae 3-5 µm wide and with narrow (1-2 µm) lumina epihymenium: inspersed with fine granules (soluble in K) hymenium: hyaline, 50-70 µm tall; paraphyses: tips thin and hyaline or pale brown; subhymenium: pale yellowish brown, 18-25(-50) µm; hypothecium: hyaline to pale yellow, 25-50 µm thick (to 150-300 µm thick in center or in areas where hyphal bundles extend into the algal layers), hyphae randomly oriented asci: clavate, 8-spored ascospores: hyaline, simple, +ellipsoid, 8-13(15) x (3.5-)4.5-7 µm Pycnidia: infrequent, scattered, and inconspicuous, immersed; conidiophores: type III of Vobis (1980) Spot tests: thallus (in the Sonoran region) usually K-, C-, KC-, P-; cortex usually KC+ yellow; medulla usually KC- Secondary metabolites: cortex with usnic acid, or occasionally (e.g., v. brunneola) isousnic acid; medulla almost always with zeorin, usually also leucotylin, other triterpenes, and fatty acids, and occasionally various depsides, depsidones or unknowns. Substrate and ecology: on basalt, pumice, rhyolite, granite, sandstone, and limestone; occasional on bark, in a wide range of communities

World distribution:

eurytemperate, subcosmopolitan in Europe, Asia, North America, South America, Africa, Macaronesia, Oceania, and Australasia