Polyblastia abscondita (Nyl.) Arnold

      Thallus crustose, endolithic and somewhat epilithic, pale brownish, gray-brownish. Globular perithecia, 0.2-0.3 mm, completely buried in pits and separated from the substrate by a thin crevice, black, no involucrellum. Hymenial gel: I + mahogany or I + blue (at low concentration). Utriform asci with (6) 8 spores. Spores elliptical bitunicate, submuriform to muriform, sometimes appearing 1-septate (by a line of dehiscence?), hyaline, sometimes yellowish in old age, 30-45 x 18-22 µm according to the literature; 30-39 x 15-20 µm according to our measurements. Photobiont: chlorococcoid. No significant chemical reactions. Rare species with mountain tendencies, occuring on hard limestone rocks more or less humid and sheltered.

N.B. Species synonymized by some authors with Polyblastia albida whose thallus is more whitish.