Scytinium gelatinosum (Wirth.) Otalora, P. M. Jorg & Wedin.

    Thallus foliose, small tuft-forming, lobes membranous, more or less overlapping and erect, apices round and often lacerate, upper surface without isidia, with a distinct network of veins, brown-greenish, brownish. Apothecia more or less abundant, sometimes absent, 0.5-1 mm diam., dark brown-red, brownish, exciple smooth, regular, without isidia. Ascospores muriform, 5-7-septate, 22-42 x 11-17 µm. Photobiont: Nostoc. Chemical spot tests negative. Not especially maritime, on mossy calcareous soils and rocks. N.B. Easily mistaken with Leptogium lichenoides of which margins have isidia-like extensions resulting in an appearance of minute dense ciliate tufts, but the latter grows on trunks at the base of mossy trees in old oceanic forests. N.B. In the field, some Leptogium species are difficult to distinguish from some Collema species.*