Slideshow image
Catillaria lenticularis (Ach.) Th. Fr.
Family: Catillariaceae
[Arthonia lilliei B. de Lesd.,  more]
Catillaria lenticularis image
Thallus: crustose, usually effuse, indeterminate, ±immersed to thin and rimose-membranaceous to weakly areolate, granular, or even distinctly squamulose-areolate, 1-3(-6) cm in diam., 100-300 µm thick; prothallus: indistinct, white but in areolate forms here and there visible as a pale or pigmented delimiting border areoles: 0.2-0.5(-0.7) mm in diam. surface: white, beige or pale brown, sometimes dark brown or olivaceous due to invasive cyanobacteria, chalky, mealy to smooth or irregularly uneven with uplifted margins, esorediate cortex: phenocortex, 7-25(-40) µm thick, the end cells of the hyphae usually with brown pigment caps, when damaged only a hyaline to ±dark epinecral layer (<10 :m) is formed photobiont: Dictyochloropsis, with cells 7-15 µm in diam.; algal layer: 35-45(-70) µm thick, the algae mostly in loose clusters, always with haustoria medulla: mainly within the substrate, therefore in thick sections densely filled with substrate particles (calcium carbonate crystals) Apothecia: becoming broadly sessile or slightly constricted at base, (0.15-)0.2-0.4(-0.6) mm in diam., numerous, scattered or in small groups of 2-3, to very dense, often partly immersed especially when young disc: reddish to dark brown (when wet wax colored), rarely black (then brown when wet), flat to convex, usually epruinose; margin: thin, slightly raised, entire, finally disappearing, sometimes paler than disc, exciple: lenticularis-type, pale to dark brown at outer edge (many hyphae with brown apical caps), not carbonaceous, K+ purple, pale brown to hyaline within, of conglutinate hyphae epihymenium: pale to dark brown, K-, N-, granular, 6-15 µm thick hymenium: hyaline, occasionally slightly inspersed, I+ blue then wine red, (35-)40-60(-70) µm tall; paraphyses: simple, easily free, the tips capitate with dark brown pigment within the walls; hypothecium: ±hyaline, K-, I-, 50-130 µm thick asci: subcylindrical, tholus I+ blue, gelatinous coat I+ violet, (30-)35-45(43) x (7-)10-15 µm, with 1-1.8 µm thick wall, 8-spored ascospores: hyaline, 1-septate, 7-10(-12) x (2-)2.5-3.5(-4) µm, oblong or oblong-ellipsoid Pycnidia: globose-ovoid, (50-)70-80 µm in diam., the wall brown, the outer cells with dark pigment caps conidia: ellipsoid to short-cylindrical, 2-3.5 x 0.7-1.3 µm Spot tests: thallus K-, C-, KC-, P-; medulla I- Secondary metabolites: none detected. Substrate and ecology: on limestones and other highly calcareous substrates (e.g., mortar) and eutrophic silicates and schist World distribution: widespread in Europe and less common in North America Sonoran distribution: Arizona and southern California. Notes: Catillaria lenticularis is very similar to C. chalybeia but differs from that species especially in having a hyaline hypothecium and non-carbonized exciple, and in usually occurring on siliceous rather than calcareous rocks. The hyaline hypothecium also separates it from the corticolous species C. nigroclavata. Reports of C. lenticularis from southern California include the var. vulgaris (Körb.) Th. Fr. (sensu Th. Fr., = Catillaria chalybeia), and f. athallina (Arnold) Hasse and f. acrustacea (Hepp ex Arnold) Hasse (both = Toninia athallina). Hasse described the spores of C. lenticularis as being fusiform-ellipsoid and acuminate at both ends. Kilias described the ascus type of this species as being "Lecanora-type". The dark capped paraphyses help distinguish the species from Lecania species that may occur in the same habitat. At least some very recently collected specimens were identified as this species from the Sonoran region