Flora of New Zealand Series

P. horizontalis var. muscorum f. albido-pruinosa Murray, T.R.S.N.Z. (Bot.) 88: 391 (1960).

P. horizontalis var. muscorum f.albido-pruinosa. Holotype: New Zealand. Otago, Matukituki Valley, 1300 m. D. Scott 4389, OTA!

Thallus in neat rosettes to 5 cm diam., ± flattened. Upper surface olive-green or yellowish-olive brown to greyish-blue tinged brownish, matt, glossy in parts, rarely delicately white-pruinose in parts imparting a slightly frosted appearance to lobes, margins incised-lacerate or minutely crenate-lobulate. Lower surface white, densely arachnoid, veins pale to dark brown, broad, flat, anastomosing, 0.2-0.8 mm wide. Rhizines white to dark brown, densely fasciculate, short, to 2 mm long. Apothecia flat, horizontal, 2-3(-5) mm diam., distinctly raised above thalline margin, disc red-brown, margins pale buff, corrugate, exciple below corrugate-scabrid-tomentose. Ascospores uniformly 3-septate, colourless to pale brownish, 26-32(-38) × 5-8 µm. Chemistry: TLC nil, or occasionally a trace of an unidentified compound.

S: Marlborough (Avon Valley), Canterbury (Hanmer to Lake Ohau), Otago (West Matukituki Valley). Alpine-subalpine on soil or among mosses in moist, shaded habitats, often on rocks at the sides of small streams in humid, shaded gullies. It seems most common east of the Main Divide from Marlborough to Otago.

Australasian