Caloplaca lactea (A. Massal.) Zahlbr.

    Thallus crustose, thin, sometimes hardly visible, whitish, prothallus usually inconspicuous. Apothecia small, scarce, 0.1-0.3 mm diam., scattered all over the thallus, sometimes leaving small cup-shaped depressions on thallus surface after falling down, disc flat, pale orange, pale yellow-orange, slightly transluscent when moist, exciple persistent, conspicuous, prominent, concolourous or slightly paler. Ascospores polarilocular, constricted septum to 1-2 µm (1/8 of the ascospore overall length), 11-14 x 6-8.5 µm. Photobiont: chlorococcoid. Thallus: K-; apothecia: K+ purple. Rare in our prospection area, on calcareous rocks, near the seashore.*