Arthonia anombrophila Coppins & P. James

     Thallus crustose, thin and submerged in the bark, relatively smooth, greyish, greenish gray, gray-purplish, brownish prothallus present in mosaic cases. Apothecia numerous and scattered throughout the thallus, "arthonoid" rarely simple and most often in coarse and irregular stars, not very prominent, blackish-brown, brown, flat disc inconspicuous, black, powdered whitish or greyish at the margin or in the center on the disc especially in the youth but not or little in the old age. Utriform asci, 30-40 x 14-18 µm according to our measurements. Ascospores small, club-shaped, colorless but may turn brown with age, (1) 2-3 times septate with a much larger terminal cell (appearance of an officer's, lieutenant or captain's epaulette!), 14-18 x 4 , 5-6 µm according to the literature; 14-16 x 5-6 µm according to our measurements. Rare, black pycnidia No significant color chemical reactions. Rare and localized species, occurring on the bark of the trunks of old trees of humid oceanic forests. N.B. Species requiring microscopic examination for a reliable determination, because very similar macroscopically to many species coming in the same environment.