Flora of New Zealand Series

Holotype: DJ. Galloway, 20 March, 1979, CHR 343256! Isotype in BM!

Thallus orbicular to spreading, ± entangled, to 18 cm diam., loosely to closely attached. Lobes linear-elongate (3-)5-8(-14) mm wide, 1.5-6.0 cm long, ± subcanaliculate, subdichotomously branched, discrete, margins entire, sinuous, slightly thickened below, faintly white-pubescent towards apices. Upper surface dark greyish-blue to blue-green, tinged brownish at margins when wet, pale greyish-fawn when dry, minutely scabrid, coriaceous, uneven or very slightly wrinkled-undulate, without isidia, soredia or pseudocyphellae. Medulla white. Photobiont blue-green. Lower surface densely tomentose to margins, occasionally naked centrally, pale buff at margins, dark brown to black centrally, tomentum thick, silky, pale whitish to dark brown, occasionally in scattered, squarrose tufts. Pseudocyphellae white, scattered, conspicuous, round to irregular, 0.5-2.5 mm wide, plane to concave, with a raised margin at maturity, often sunk in tomentum. Apothecia not seen. Pycnidia sparse to frequent, immersed, 1.5 mm diam., visible as hemispherical swellings on lower surface. Chemistry: 7β-acetoxyhopan-22-ol and hopane-15α, 22-diol.

S: Canterbury, Peel Forest. Type locality: New Zealand. Canterbury. Peel Forest. On fallen Pseudowintera on bank of stream on way to Emily Falls.

Endemic

P. allanii is closely related to P. coriacea and often forms photosymbiodemes with this species. It is known only from Peel Forest on the south-eastern slopes of Mt Peel. It most commonly occurs as an epiphyte of Myrsine australis [Renner and Galloway loc. cit.].

P. allanii is most clearly distinguished from P. coriacea when wet, the thallus appearing dark greyish-blue to blackish. It has entire margins which separate it from the marginally phyllidiate P. fimbriatoides. It associates with P. episticta and P. homoeophylla but its ecology is still poorly known. Myrsine and Pseudowintera are its two presently known phorophytes. It is still much in need of study and collection.