Verrucaria macrostoma f. furfuracea de Lesd.
This taxon differs from Verrucaria macrostoma by its thallus minutely areolate and partly squamulose, notably towards the margin, and mostly by soredia and propagules towards the margin of areoles, brownish with pale brown soredia and pale brown propagules when dry, green when moist with soredia and propagules turning to yellowish. Perithecia are less numerous than in the canonical type. This taxon is less frequent than the type, on mortar of very humid and shaded walls near the seashores. N.B. This taxon (not recognized by all authors) hardly deserve the level of morph since all intermediate specimen with the type are observed. See Verrucaria nigrescens var. nigrescens f. tectorum that is very similar and often confused, but hardly turns to green when moist and isidiate (or blastidiate).