Acrocordia macrospora A. Massal

     Thallus superficial, smooth or rimose, whitish with grey to grey-brown zones, greyish to grey-brown, dirty ochre without pink even fresh. Perithecia black, only half immersed in thallus, 0.7-1.5 mm diam., rather prominent, ostiole not papilla-like; involucrellum ± spreading laterally, never continuous below the exciple (visible on section). Spores largely ellipsoid, with round-shaped extremity (but sometimes slightly sharp), uni-septate, 19-30 x 8-14 µm. Pycnidia black, 0.2-0.3 mm diam., usually few. Photobiont: Trentepolhia. Chemical spot tests negative. Relatively rare species developing on sheltered, often shaded siliceous or weakly calcareous walls of chapel enclosures, in aerohaline zone of coastal areas. Resembles Acrocordia conoidea  but the perithecia are not flattened, lack papillate ostioles and the ascospores are larger, Acrocordia salweyi  is distinguished in section by the tightly incurved involucrellum which is often continuous below the true exciple; it occurs on strongly calcareous substrata and mortar in old walls. N.B. There are some confusing intermediate specimen mainly regarding the spore sizes between Acrocordia conoidea and Acrocordia macrospora particularly on some rocks: Kersantite, Dolerite, etc.*