Fuscidea lightfootii (Sm.) Coppins & James
Thallus crustose, 1-3 cm diam., made of convex areoles, to 0.2-0.3 mm, granular, finely to coarsely verrucose-areolate, occasionally ± papillate, grey-greenish, bright olive to dull grey-green or suffused brownish in places, usually sorediate with granular soralia pale, green-yellowish notably towards margin, prothallus pale brownish-grey or whitish. Apothecia frequent, 0.5-1 mm diam., disc flat to slightly convex, brown-blackish to blackish, margin uneven, flexuose or lobate, concolourous or paler, somehow crenelated or sometime fluted. Ascospores simple, colourless, broadly ellipsoid, crowded towards the center, with obtuse ends (dumb-bell shape), 8-11 x 3.5-4.5 µm. Photobiont: Trebouxioide. Chemical spot tests negative but UV+ whitish. Grows on horizontal twigs of Salix and Fraxinus in wet lands.
See Lecidella elaeochroma very common species with a less granular thallus and C+ orange.*
