Parmelia tenuirima Hook.f. & Taylor
P. tenuiscypha Taylor, Hook. Lond. J. Bot. 6: 175 (1847).
Aspidelia beckettii Stirton, T.N.Z.I. 32: 81 (1900).
Aspidelia beckettii. Holotype: New Zealand. Canterbury, Oxford Bush, 1895. T.W.N. Beckett, BM!
P. tenuirima var. platyna. Lectotype: New Zealand. Otago, Mt Cargill, Dunedin. On Nothofagus. J.S. Thomson ZA 56, CHR 160205!
Thallus thin and papery, orbicular to spreading, often in very large rosettes to 20(-40) cm diam., ± loosely attached, corticolous, very rarely saxicolous. Lobes broadly rounded (5-25 mm wide) or slightly elongate-imbricate, margins rounded, entire, with a fine, black or brown shining rim, occasionally developing crowded lobules centrally. Upper surface smooth, rarely faveolate-cracked centrally, shining, undulate, greyish-green, not darker at margins, often with a bluish tinge, pseudocyphellae small, white, sigmoid, scattered evenly over upper surface, often minute and crowded at lobe margins but not forming a reticulum of white lines. Lower surface black, smooth with a narrow, brown, naked marginal zone, rhizinate centrally. Rhizines black, sparse to numerous, simple to squarrosely branched. Apothecia common, pedicellate, to 15 mm diam., disc plane or subconcave, matt, reddish-brown to yellowish-brown, greenish-blue in shaded specimens, often centrally perforate, margins entire, thalline exciple smooth, shining, concolorous with Thallus, maculate or pseudocyphellate. Ascospores ellipsoid, 14-16 × 8-12 µm. Chemistry: Cortex K+ yellow; medulla K+ yellow → red, C-, KC+ red, Pd+ orange. Salazinic acid and atranorin.
N: Gisborne (Lake Waikaremoana), Wellington (Waipakahi Valley Pongaroa, Manawatu). S: Nelson (Tophouse) to Southland. St: Widespread, as an epiphyte of Nothofagus, lowland to subalpine.
Australasian
P. tenuirima is a corticolous species (occasionally it will overgrow boulders at the foot of a tree trunk but it is almost always entirely corticolous) characterised by broad, rounded papery lobes, the predominantly simple rhizines, the often perforate apothecial discs and the scattered pseudocyphellae. It is the largest Parmelia in Nothofagus forests of South I., and at forest margins the large rosettes are visually arresting. On Nothofagus and Griselinia, its two most common substrates, it associates with Lobaria adscripta and several species of Pseudocyphellaria and Sphaerophorus. It is rarely if ever found on twigs, and appears more common in the forests of South I., than those of North I., where it is frequently replaced by P. erumpens. It is rare on Podocarpus totara in Stewart I.
