Bacidia sipmanii M. Brand, Coppins, van den Boom & Sérus.
Thallus crustose, thin and tightly appressed, smooth to minutely warted, rimose, earthenware-like cracked, grey-greenish, pale green, pale greenish when moist, grey-yellow-greenish when dry, without isidiform or sorediform protuberances. Prothallus absent or rarely whitish. Apothecia often few in number, strongly convex and even tuberculate, 0.5-1 mm in diameter, disc flat then domed, pale brown to dark brown with pink tones, greyish-brown, thick margin, greyish-blackish disappearing at the end. Ascospores and microscopic characteristics as Bacidia scopulicola. Pycnidia often numerous. Chemical spot tests negative. On coastal rocks more or less siliceous exposed to South in the xeric-supralittoral zone often with Bacidia scopulicola. N.B. Intermediate morphs and even chimera between these two taxa exist: see Bacidia scopulicola forma. Cf. in the cavities of rocks without or little acid Bacidia fuscoviridis sorediate and without pycnidia and with a white prothallus.