Flora of New Zealand Series

Lichen concolor Dickson, Fasc. pl. cryptog. brit. 3: 18 (1793).

Thallus dispersed as an indeterminate, scurfy, ± areolate crust, closely attached, often forming extensive colonies, corticolous. Lobes very minute, often only visible at margins of thallus, margins partly entire to completely and densely granular-sorediate. Upper surface lemon-yellow to mustard-yellow, often greenish in shaded habitats, ± densely granular-sorediate or minutely granular-isidiate. Medulla very thin, white. Lower surface whitish. Rhizines simple, pale, sparse. Apothecia rare (not seen in New Zealand material) minute, yellow orange-brown with a yellow, sorediate margin. Ascospores elliptical 6-15 × 4-6 µm. Chemistry: Calycin and pulvinic dilactone.

N: S: Widely distributed on eutrophic bark, especially of introduced trees, e.g., Populus, Quercus, etc., in parks and gardens.

Cosmopolitan

Distinguished from Candelariella by the areolate, granular sorediate thallus, lobate margins and the lack of apothecia.