Flora of New Zealand Series

Holotype: New Zealand. South I. Canterbury, Arthur's Pass National Park, lower slopes of Mt Rolleston, close to bank of stream on track to Margaret's Tarn, on mossy trunks and large branches of Nothofagus solandri var. cliffortioides, 5.xi.1989, D.J. Galloway 8951 – BM.

Description : Thallus corticolous, orbicular to spreading, 3–6(–8) cm diam., loosely attached centrally, margins free and subascendent. Lobes irregularly laciniate, rounded, ±imbricate, 0.5–1 cm wide, margins irregularly notched or incised, irregularly phyllidiate, slightly thickened below, ±white-tomentose, without pseudocyphellae. Upper surface dark lead-grey or grey-blue, suffused red-brown when moist, pale grey-white or fawnish tinged brownish or reddish at margins when dry, plane, smooth or slightly wrinkled in parts, markedly scabrid-areolate (×10 lens) and occasionally patchily white-tomentose at or near margins, thick, coriaceous, flabby, pliable when moist, rather brittle when dry, phyllidiate, pseudocyphellate, without isidia, maculae or soredia. Phyllidia marginal, rather sparse, simple, lobulate to 1 mm tall, constricted at base to rarely somewhat pectinate, margins silky white-tomentose. Pseudocyphellae scattered, infrequent, minute, punctiform to raised-conical, white. Medulla white. Photobiont cyanobacterial. Lower surface white to pale pinkish buff towards centre, uniformly tomentose from margins to centre, tomentum thick, shaggy, pale-buff or whitish. Pseudocyphellae white, scattered, sunk in tomentum, round to irregular, 0.1–0.5(–1) mm diam., margins slightly raised, decorticate area roughened. Apothecia and pycnidia not seen.

Chemistry : 7β-acetoxyhopan-22-ol, hopane-7β,22-diol (tr.), hopane-15α,22-diol.

S: Canterbury. Known only from the type locality.

Endemic

Illustrations : Galloway (1993a: 346, fig. 1; 347, figs 2–5).

Pseudocyphellaria halei is characterised by: rounded, rather imbricate lobes with sparingly phyllidiate margins also furnished with a silky white tomentum; a white medulla; a cyanobacterial photobiont; a characteristic scabrid-areolate upper surface, patchily tomentose towards margins; laminal white, punctiform pseudocyphellae; and a two-hopane chemistry