Umbilicaria hyperborea (Ach.) Hoffm.
Lichen hyperboreus Ach., K. Vet. Acad. nya Handl. 15: 89 (1794).
Thallus 2-5(-10) cm diam., monophyllous, but occurring with secondary lobules over the umbo and appearing polyphyllous, rigid to thin and pliable, umbo moderate to elevated, smooth to wrinkled or subgranular. Upper surface undulate or uneven, covered with a pattern of narrow, vermiform ridges extending to margins, in between ridges thallus appears darker, margins entire to unequal, rounded or lacerate, sometimes squamulose, surface dull to subnitid, greenish- grey, dark brown, greyish- brown or olive-brown. Lower surface bullate to lacunose, rarely plane, smooth to granular, grey-brown to brown-black, rhizines absent. Apothecia common, 1-2 mm diam., sessile, scattered almost to umbo, usually developed between ridges, free, circular to irregular, disc black, convex, regularly gyrose. Hymenium to 85 µm tall. Paraphyses simple, septate, rarely branched colourless. Hypothecium 140-160 µm thick, brown, irregular. Ascospores colourless 6.6-19.8 × 3.3-8 µm.
N: Mt Ruapehu. S: Canterbury (Mt Torlesse, Port Hills), Otago (Mt Ida, Mt St Mary, Mt Pisgah). On subalpine or alpine rocks and probably more widespread than records show.
Cosmopolitan
