Tephromela atra var. torulosa (Flörke) Hafellner

    Thallus crustose, 3-6 cm diam., areolate to verrucose, pale grey-greenish, dull grey-greenish, dull white, often tinged-green (algae?), prothallus conspicuous, black. Apothecia more or less rounded and irregular, 1-2.5 mm diam., disc flat to slightly convex, smooth, black, exciple wavy and slightly crenulate or bumpy, whitish. Ascospores: as the canonical type ; 10-12 x 6-7 µm according to our measurements. Photobiont: Chlorococcoid. C-, K+ yellow, Pd-, I+. This variety is far less common than the canonical type and grows on smooth bark of deciduous trees in dusty and nutrient-rich zones.

_ See Rinodina roboris of which the thallus is greener and devoid of black prothallus and the apothecia smaller, markedly convex.