Umbilicaria subglabra (Nyl.) Harm.
Gyrophora subglabra Nyl., Lich. env. Paris: 135 (1896).
Thallus (2-)4-6(-8) cm diam., mono- to polyphyllous, ± rounded to irregular, margins incised-ragged or with a few, scattered pinholes, often inrolled or ascending when dry. Upper surface dull, smooth or minutely roughened, dark grey or brown-grey, rarely blackened towards margins, ± pale grey-white centrally, ± white-pruinose centrally and there minutely but consistently radially cracked, often ± areolate above umbo, cracks scarcely noticeable at margins. Lower surface uniformly black, blotchy, greyish at margins and umbo, without rhizines, smooth, ± coriaceous, dull. Apothecia not seen.
S: Canterbury (Glen Lyon Station near Lake Ohau). On alpine rocks 1700-2000 m. Still very poorly collected in New Zealand.
Bipolar