Thamnolia vermicularis  

Thallus prostrate or decumbent, straggling, occasionally ± densely tufted, to ca 50 mm in length and 1-2 mm diam., not or sparingly branched, the branches chalk-white, hollow, cylindrical, smooth, worm-like, the apices pointed, the base usually dying with the thalline units becoming vagrant. Cortex composed of longitudinally orientated hyphae. Medulla thin, also of longitudinally orientated hyphae. Soredia and isidia absent. Photobiont trebouxioid.
Anamorph: conidiomata formed as small pustules on the thallus surface, 200–350 µm diam. and 150–200 µm tall,  ± hemispherical, the surface irregular, ostiolate, with pinkish exudates formed by a mucilaginous mass of conidia. Conidiophores elongate, forming chains of intercalary conidiogenous cells with peg-like processes near the upper cell septum. Conidia 3-5 x 1-2 µm, bacilliform, tapering slightly at one end, hyaline aseptate, thin-walled.
Teleomorph: not known.
Chemistry:  thallus C–, K+ pale yellow, KC–, Pd+ yellow, UV+ white (baeomycesic and squamatic acids).