Nephroma resupinatum (L.) Ach.

    Thallus foliose, usually rosette forming, 5-15 cm accross, lobate, lobes entire, intertwined, wavy, sometimes ascending, upper surface more or less smooth to subtomentose with phyllidia (lobulliform isidia), notably towards the margin, grey-brownish when dry, olive-brown when moist, lower surface tomentose to felted, dull white-ochre to pale brown-ginger, scattered with minute white cottony papillae, 0.5-1 mm diam., medulla white. Apothecia frequent, located at the ascending and upturned lower surface lobe margins, kidney-shaped or hood-shaped, 0.5-1 cm accross, thalline exciple entire, bent toward the disc when dry, disc circular to oval, dark brown-orange, apothecia lower surface tomentose. Ascii 8-spored, 60-80 x 20-25 µm according to our measures. Ascospores pale brown, fusiform, 3-septate, 21-24 x 4-6 µm according to literature, 22-24 x 5-6 µm according to our measures. Photobiont: Nostoc. Chemical spot tests negative. Montane, belongs to the Lobarion pulmonariae and grows on mossy barks of old deciduous trees (seldom on coniferous or mossy rocks) in old humid woodlands subjected to oceanic influence. See also Nephroma laevigatum of which thallus lower surface is not tomentose.