Sticta fuliginosa (Hoffm.) Ach. s. l.
In accordance with the s.l. denomination used in the present description, here we consider a complex of species. Thallus foliose, made of large lobes, more or less ascending, up to 2-3 cm wide, apices rounded and rolled up, upper surface grey-brownish, dark greyish, darkened with numerous cylindrical isidia, black, clustered in coralloid patches, lower surface pubescent, pale brown, with paler and irregular in shape pseudocyphella. Apothecia very rare, outbreaks seemingly random and seasonal, fleeting, distributed in lines towards the upper surface margins, as the ocelli of butterfly's wings, 2-3 cm diam., disc brown-red, thalline exciple markedly ciliate, white at first, then somewhat ciliate-crenulate, and excluded when mature at a time where the disc solely remains as a dull brown-reddish small dome-shaped protuberance. Ascospores ellipsoid, slightly curved, apices pointed, 1-septate, 30-33 x 5-9 µm. Photobiont: Nostoc. Chemical spot tests negative but fresh specimen have a fish smell. Rare, on rocks and at the base of mossy trunks in humid locations subjected to oceanic climate. N.B. Young specimen of which the lobes are not yet darkened with isidia are easily confused with Sticta sylvatica.*
Recently, this complex was divided into 4 different species, 3 of them being found in Brittany: Sticta fuliginosa ss. stricto ; Sticta ciliata ; Sticta fuliginoïdes, the fourth being found in Ireland and Azores, Sticta atlantica. We retain this level of classification in order to allow the positioning of ancient specimen. For more details, refer to:
MAGAIN N., SERUSIAUX E. Mycol Progress (2015) 14:97. Dismantling the treasured flagship lichen Sticta fuliginosa (Peltigerales) into four species in Western Europe. Download available at: http://hdl.handle.net/2268/186416