Haematomma ochroleucum (Neck.) J. R. Laundon var. ochroleucum

    Thallus crustose, up to 10 cm diam., more or less smooth, slightly leprose, sometimes with more or less numerous soredia, grey-yellowish, pale greyish with ochre or yellow tinge, prothallus cotonny, fimbriate, dull whitish. Apothecia usually numerous, irregular and at various growth stages, 0.5-2 mm diam., arising from thallus swellings or tears, immersed at first then slightly prominent, , disc scarlet, margin slightly sorediate. Ascospores fusiform, 3-7-septate, 30-60 x 5-7 µm. Pycnidia red, 0.2 mm diam.. Photobiont: Trebouxioid. Thallus: C-, K+ pale yellow, Pd+ pale yellow, apothecia : K+ purple. Var. ochroleucum grows on dry surfaces of rocks or dry walls of buildings notably chapels. See  Haematomma ochroleucum var. porphyrium which is more whitish or pale gey-greenish and less fertile. N.B. To some authors, these two varieties are only chemotypes.