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Toninia candida (Weber) Th. Fr.
Family: Ramalinaceae
[Biatora candida (Weber) Hepp,  more]
Toninia candida image
Life habit: lichenized, lichenicolous at least when young Thallus: squamulose, rosulate, up to 40 mm diam. squamules: up to 5 mm diam., more less scattered and rounded when young, later adjacent or sometimes slightly imbricate, marginal squamules weakly concave to weakly convex, forming ± radiating lobes, central squamules more rounded and convex upper surface: white, entirely covered by farinose pruina, dull, smooth, lacking pores and pseudocyphellae upper cortex: up to 60 µm high, containing calcium oxalate margin: concolorous with upper surface Apothecia: up to 2 mm diam., remaining ± plane and marginate, densely pruinose; exciple: dark gray in the rim, reddish brown in inner part; hypothecium: reddish brown; epithecium: gray (K+ violet, N+ violet) asci: clavate, 8-spored ascospores: fusiform, 1-septate, 15-24 x 3-4 µm Pycnidia: not seen Spot tests: all negative Secondary metabolites: none detected. Host: cyanolichens, especially Collema Substrate and ecology: on calciferous rock on steep to overhanging rock walls, usually somewhat shady, in pinyon-juniper woodland and conifer forests at 1650-2130 m World distribution: widely distributed in the temperate region of the Northern Hemisphere Sonoran distribution: uncommon in Arizona.