Pseudocyphellaria ardesiaca D.J.Galloway
Holotype: New Zealand. Canterbury, Boyle River, near Lewis Pass, on bark of Leptospermum on terrace overlooking Boyle Lodge, 9 January, 1979. D.J. Galloway, CHR 343237! Isotype in BM.
Thallus ± orbicular to spreading, 2-6(-9) cm diam., often in small, closely attached rosettes. Lobes rounded to elongate-laciniate, imbricate, to 2 cm wide, margins crenulate-incised, sorediate, often sinuous. Upper surface dark bluish-purple when wet, pale blue-greyish-fawn when dry, conspicuously maculate (×10 lens), smooth, slightly scabrid at lobe apices, undulate, wrinkled-corrugate centrally, matt or shining, sorediate, without isidia or pseudocyphellae. Soredia golden yellow often somewhat reddish, coarse, granular, crowded, mainly marginal in ± continuous, erose to convolute-congested soralia, occasionally laminal on weakly defined ridges. Medulla yellow. Photobiont blue-green. Lower surface pale yellow, tomentose to margins, tomentum short, even, pale yellowish-white, brownish centrally. Pseudocyphellae golden-yellow, scattered, sparse, without a defined margin, 0.1-0.4 mm diam. Apothecia not seen. Chemistry: Pulvinic lactone, pulvinic acid, calycin, 2α-acetoxystictane-3β,22α-diol, 2α,3β,22α-triacetoxystictane, 2α,3β-diacetoxystictan-22α-ol,stictane-3β,22α-diol (±), 3β-acetoxystictane-2α,22α-diol (±), stictane-2α,3β,22α-triol (±). (Dr A.L. Wilkins in litt.).
N: South Auckland (Taupo), Wellington (Volcanic Plateau south to Taihape and eastwards to Kaimanawa Ra.). S: Nelson (Lake Rotoiti), Canterbury (Lewis Pass to Peel Forest). On trees and shrubs mainly east of the Main Divide in South I., subalpine.
Australasian
P. ardesiaca is a small, corticolous, rosette-forming species characterised by the grey-blue thallus, the yellow medulla and the marginal yellow soralia. It is distinguished from P. coerulescens by the presence of soralia and from P. aurata in the nature of the soralia and in the photobiont. It seems similar but distinct from P. encoensis R. Sant. , nom. nud. which is found in southern Chile [Huneck et al., J. Hattori bot. Lab. 37: 548(1973)].
