Squamarina calesensis Cl. Roux & Poumarat
in Roux & al., Bull. Soc. linn. Provence, 75: 87, 2024.
Synonyms:
Distribution:
Description: Thallus squamulose, the squamules overlapping, pale green when fresh, turning brownish in the herbarium, more or less white-pruinose, the margins of peripheral squamules usually white, the lower surface pale in young squamules, then black, attached by numerous, concolorous rhizinoid hyphal strands. Upper cortex 40-50 µm thick, consisting of a distinct epinecral layer inspersed with crystals, and a 34-40 µm thick layer of mainly anticlinally arranged hyphae inspersed with crystals; medulla white (brownish in lower part), 0.2-0.3 mm thick in the peripheral squamules, 0.4-0.9 mm thick in the central ones. Apothecia frequent, lecanorine or finally weakly zeorine, 0.7-3.3 mm across, at first adnate, then strongly constricted at base, with a chestnut brown, epruinose or faintly pruinose, at first concave then flat to finally convex disc and a white-pruinose, smooth, usually long-persistent thalline margin, the proper margin thin and poorly evident, somehow glossy, level with disc. Thalline exciple 280–385 µm wide at base, corticate; proper exciple filled with crystals, of mainly anticlinally arranged hyphae with elongated cells; epithecium brownish, granular, 20-30 µm high; hymenium colourless, 70-90 µm high, hemiamyloid; paraphyses coherent, branched in upper part, 1-1.5 μm thick at mid-level, the apical cells 2.5-5.5 μm wide; hypothecium colourless, prosoplectenchymatous, with crystals soluble in K and insoluble in N, I- (the subhymenium is devoid of crystals and reacts I+ blue). Asci 8-spored, elongate-clavate, with a thin, outer amyloid layer and a thickened, amyloid tholus devoid of an ocular chamber, penetrated by an axial tube the sides of which stain I+ deeper blue, approaching the Porpidia-type. Ascospores 1-celled, hyaline, ellipsoid, ovoid or rarely subfusiform, (8.5-)9-5- 13.5(-15) x (4-)4.5-5.5 µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC- (or cortex KC+ faintly yellow), P-. Chemistry: cortex with usnic and isousnic acids.Note: a recently-described species of soft calcareous rocks, hitherto known only from the type collection, but according to Roux & al. (2024) probably more widespread in the Mediterranean region. Saxicolous samples of S. paradoxa from Italy should be compared with this species, which should be looked for in Mediterranean Italy.
Growth form: Squamulose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Poorly known taxon in need of further study
Predictive model
Growth form: Squamulose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Poorly known taxon in need of further study
Predictive model
