Flora of New Zealand Series

Lichen croceus L., Sp. Pl.: 1149 (1753).

Thallus foliose, distinctly dorsiventral, 1 - 10 cm broad. Lobes rounded, margins entire, often slightly raised. Upper surface greenish-brown when wet, red- brown when dry, rather scabrid. Photobiont rather discontinuous below upper cortex. Cephalodia internal in ± ovoid colonies above lower surface. Medulla orange (solorinic acid, K+ purple). Lower surface bright orange (solorinic acid), tomentose with a reticulum of brown veins often present. Apothecia oblong to round, plane, not depressed into thallus, disc dark brown, to 1 cm diam. Asci 6-8-spored. Ascospores 1-septate, oblong-ellipsoid, hyaline, becoming brown, 25-45 × 10-12 µm. Chemistry: Thallus and medulla K+ purple. Solorinic acid.

S: Nelson (Waiau Pass), Canterbury (Torlesse Ra., Mt Hutt, Mt Peel), Otago (Pisa Ra., Old Man Ra., Remarkables, Coronet Peak), from 1600-2200 m. On soil in damp, mainly south-facing slopes.

Bipolar

S. crocea is found in New Zealand on subalpine soils on the mountains of Eastern Canterbury and Central Otago, with the most northerly record being from Waiau Pass [Galloway and Simpson N.Z. J. Bot. 16: 523 (1978)]. It is not a common species in any of the known localities, though it is immediately recognised by the bright orange lower margin to the thallus lobes. In the Northern Hemisphere it is a high-arctic circumpolar species, widespread and common at Northern Hemisphere it is a high-arctic circumpolar species, widespread and common at northern latitudes particularly in oceanic areas. It is restricted to high ground in the south of its range, being known from the European Alps, the Carpathian and Ural Mountains, the Pyrenees and the Rockies. It occurs also in Japan and the mountains of Java [Gilbert Lichenologist 7: 190-192 (1975)]. Although occurring in fellfield vegetation on some South I., mountains it is not known from either North or Stewart I., Australia, South America or Antarctica.