Scytinium teretiusculum (Walbr.) Otalora, P.M. Jorg. & Wedin

      Thallus with the appearance of a small carpet formed of tiny lobes of 0.5-1 x 0.2-0.5 mm, branched and intermingled, bearing small formations in the form of isidia, simple or coralloid, erect, of 100 µm in diameter and 0.5-1 mm high, often very numerous and may obscure the lobes, greyish-brown in dry weather, brownish, blackish-brown in wet weather. Apothecia very rare, urceolate, reddish-brown disc. Spores hyaline, elliptical, muriform, 20-30 x 8-12 µm. Photobiont: Nostoc. No significant color chemical reactions. Not very rare but unnoticed species, growing on the rough and mossy bark of deciduous trees, sometimes on the ground among the mosses of the dunes rich in calcareous shells, also on the mortar of old walls.

Cf. Scytinium tenuissimum with lacerated lobes and usually fertile.

Cf. Scytinium schraderi with thicker thallus and cylindrical lobes without isidioid formations.