Thallus crustose, effuse, ± dispersed, ± shining, no cortex, but in the uppermost part a somewhat denser hyphal tissue, prothallus indistinct or only slightly developed between the patches of thallus. Photobiontgreen, ?. Apothecia sessile, rounded, lecideine, black, sometimes with a white pruina, thalline exciple well-developed, smooth, uneven or sometimes with short, irregular hairs. Paraphyses richly branched and anastomosing, usually covering the asci like nets. Hypothecium dark purplish-brown. Asci thick-walled, 1-8-spored. Ascospores transversely septate, submuriform or muriform, colourless.