Toninia candida (Weber) Th. Fr.
Thalloidima candidum (Weber) A. Massal.
Thallus in a rosette of 2-5 cm in diameter, more or less lobed at the margin, formed of rounded and pleated scales, rough, chalky surface, appearing mealy because strongly powdery whitish, the general color is whitish, grayish-white, becoming whitish-brownish if wet. Apothecia regularly applied to the thallus, disc 1-4 mm in diameter, flat, blackish but appearing greyish-bluish under the bloom, very thin margin, persistent. Fusiform spores, 1-septate, 14-26 x 3-5 µm. Mediterranean thermophilic species coming on well exposed limestone rocks.