Placynthiella icmalea (Ach.) Coppins & P. James
Thallus crustose, spreading, more or less cracked, composed of minute granules, coralloid isidia-like, 25-200 µm tall, dark brown, blackish. Apothecia most often absent, or inconspicuous and scattered all over the thallus, 0.2-0.6 mm diam., disc brown-reddish, exciple paler. Ascospores colourless, simple, 1-septate, 8-12 x 4-5 µm. Photobiont: Chlorella. C+ pale red, K-, KC+ red, Pd-. Rather common, on soils, enriched in organic matter, amongst other lichens, occasionally on wood.*