Flora of New Zealand Series

Holotype: New Zealand. Nelson, West Bay, Lake Rotoiti. On bark of Leptospermum ericoides. 15 November, 1977, DJ. Galloway, CHR 381001!

Thallus spreading, ± loosely attached, margins ± free and subascendent, to 20 cm diam. Lobes linear-elongate, 5-10 mm wide and 3-5 cm long, ± laciniate, subdichotomously to irregularly branching, margins entire or slightly incised, slightly thickened, ± incurled, brown-pubescent, apices crenulate, sinuous or truncate. Upper surface reddish when wet, pale greyish-fawn or tinged yellowish when dry, shallowly reticulate-faveolate, uneven or smooth, shining, without soredia, isidia, maculae or pseudocyphellae. Medulla white. Photobiont blue-green. Lower surface densely and thickly tomentose to the margins, or with a narrow, glabrous, marginal zone, tomentum dense, brown to blackish. Pseudocyphellae yellow, scattered, round to irregular, frequent, verruciform, 0.1-1.0 mm diam., sunk in tomentum or protruding from it, margins conspicuous, pale to dark brown or black. Apothecia marginal or submarginal, 0.5-3.0 mm diam., sessile to subpedicellate, disc concave at first and entirely obscured by margins, plane at maturity, matt, brown-black, margins thick, persistent pale buff or flesh-coloured, coarsely scabrid-crenulate appearing ± denticulate or coronate, thalline exciple corrugate-scabrid, pale flesh-coloured. Ascospores greenish-brown, fusiform-ellipsoid, 1-3-septate, 23-30 × (3-)7-10 µm. Chemistry: Pulvinic acid, pulvinic dilactone, calycin, tenuiorin, methyl gyrophorate, hopane-6α,7β,22-triol, stictic, constictic and norstictic acids.

N: Wellington (Manawatu). S: Nelson, Westland and east of Main Divide at Lake Ohau (Canterbury) and Forest Hill (Southland). Common and often richly developed on successional shrubs (especially Leptospermum) in north-west Nelson particularly, still rather poorly known elsewhere.

Australasian

P. crassa is distinguished by the thick, felted, dark tomentum of the lower surface from which protrude yellow pseudocyphellae. The nature of the tomentum and the margins of the lobes separate it from P. maculata. It is closely related to P. carpoloma but is distinguished from it by the thicker lobes, the thick, dark tomentum on the lower surface, and by the blue-green photobiont.