Hypotrachyna minarum (Vainio) Krog & Swinscow

    Thallus usually loosely appressed to the substratum, up to 10 cm diam., lobes indented, 1-5 mm wide, upper surface turtledove grey when dry, grey-green when moist, occasionally slightly brownish towards lobe margins, black cilia absent on the surface but found exceptionally on lobe margins, dark grey isidia potentially covering the whole lobe surface, simple to branched/coralloid, not swollen, tips sometimes pale brown notably towards thallus center. Lower surface blackish, rhizines, simple. Apothecia very scarce, 1-4 mm diam., disc dark brown, exciple markedly isidiate. Utriform asci, 35-40 x 20-25 µm according to our measurements. Simple spores, widely elliptical, 12-17 x 8-10 µm according to the literature; 10-16 x 6-8 (10) µm according to our measurements. Cortex : K+ yellow; Medulla : C+ dark pink, K-, KC+ dark pink to red, Pd-, UV-. On mossy tree trunks inland, on rocks in the aerohaline zone near the seashore (seldom on rocks inland). 

_ Very close to Hypotrachyna horrescens  of which the lobes are fully covered with cilia and swollen coralloid isidia and with medulla C-, but very rare near the seashore.

_ See also Parmotrema crinitum which is K+ orange. 

N.B. Near the seashore a different morph with less indented lobes and isidia covering almost the whole thallus may be found on bark of old trees, notably Pinus sp., Hypotrachyna minarum forme corticole.