Leptogium cyanescens (Rabenh.) Körb.

    Thallus foliose, 5-10 cm across, wrinkled like paper, lobes usually clustered but sometimes isolated, not erect, 0.5-1 cm long, upper surface smooth to slightly pleated, pale grey, grey-bluish, grey-lilac, tinged blue or purple, with small cylindrical concolourous isidia, flattened towards the margins, clustered towards the center, lower surface smooth, rhizines absent, pale grey. Apothecia very rare, sessile, 1-2 mm  diam., disc brown red. Ascospores colourless, muriform, ellipsoid, 19-23 x 7-9 µm. Photobiont: Nostoc. Chemical spot tests negative. On mossy humid tree trunks and rocks.*