Sticta canariensis var. dufourii Delise

    Thallus foliose, 5-10 cm across, made of large lobes, more or less branched, 1-2 cm wide, round and erect, margin irregularly and minutely incised (lace-like), sometimes with small lobules, branched isidia (phyllidia) emerging from margin, sometimes aggregated in dense clusters, blue-blackish, potentially extending to the whole surface of the thallus, upper surface grey-olive when moist, grey-bluish to grey-brown when dry, lower surface wrinkled and minutely felted-tomentose, pale brown, slightly orange when moist, with whitish scattered and irregular  (circular to angular) cyphella, 0.3-0.8 mm diam.. Apothecia unknown in our prospection area. Photobiont: Nostoc. Chemical spot tests negative. Rare, grows at the base of mossy trunks of Fraxinus, Corylus, less frequently on Quercus in humid and shaded zones close to streams and rivers. N.B. It is the Cyanobacterial morph of Sticta canariensis s. str..*

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. Freely available: http://hdl.handle.net/2268/186416