Flora of New Zealand Series

Lichen griseus Lam., Encycl. méth. Bot. 3: 480 (1789).

Thallus irregular or orbicular, to 8 cm diam., ± closely attached, greyish to grey-brown with a whitish, usually maculate pruina which sometimes covers the whole upper surface but is more usually restricted to lobe tips, corticolous. Lobes mostly overlapping, radiating, to 3 mm broad, wider and concave at apices, isidiate. Isidia granular becoming sorediate, marginal or laminal, sometimes densely developed centrally. Lower surface whitish, centrally pale brownish. Rhizines simple, pale or brownish, becoming branched at tips. Apothecia rare, to 3 mm diam., margins sorediate. Ascospores 27-34 × 14-17 µm. Pycnidia immersed. Conidia 4-7 × 1-2 µm. Chemistry: Medulla K-, C-, KC-, Pd-. Four unidentified compounds.

N: South Auckland (Hamilton) to Wellington. S: Nelson (Lake Rotoroa). Still very rarely collected and poorly known.

Cosmopolitan