Flora of New Zealand Series

Holotype: New Zealand. South Auckland, Mamaku near Rotorua. On Leptospermum ericoides, 14 March, 1981. J.K. Bartlett, CHR 381200! Isotype in BM.

Thallus foliose, lobate, spreading, broadly attached, 5-10(-22) cm diam., thin and fragile, papery, to thick and coriaceous. Lobes 3-8(-12) mm wide, loosely subdichotomously branching near periphery, more complex-imbricate centrally, margins ± subascendent, rarely entire, crisped, somewhat thickened, often tinged brownish, ± densely isidiate. Upper surface smooth, matt, ± coriaceous, ± wrinkled-plicate in parts, bright lettuce-green when wet, superficially browned at margins or sometimes over whole thallus, pale greenish- buff when dry, isidiate. Isidia short, 0.1-0.3(-1.2) mm tall, c. 0.1 mm wide, squamiform-imbricate, ± flattened to erect, marginal at first in well-defined lines, often dense, spreading to lamina and sometimes forming a dense, diffract, fragile crust centrally. Lower surface pale buff or whitish or pinkish to pale or dark brown centrally, tomentose, tomentum regular, to margins, or only ± central with patches of shining, irregularly, pitted or wrinkled lower cortex at margins. Cyphellae 0.1-1.2 mm diam., rounded to subirregular, white. Apothecia rare, 1-3.5 mm diam., scattered, sessile to subpedicellate, disc bright orange or orange-yellow, waxy, concave at first and then often obscured by inrolled margins, plane to subconvex-undulate at maturity, margins persistent, thick, crenate, pale buff or whitish, exciple pale buff or red-brown, corrugate- scabrid, ± translucent when wet. Epithecium pale brownish-yellow, 8-13 µm thick. Hymenium 130-155 µm tall, colourless. Paraphyses moniliform, apices capitate. Ascospores biseriate, elongate-ellipsoid with pointed apices, 3-septate at maturity, 27-37 × 6.8-8.3 µm.

N: North Auckland (Three Kings Is) to near Rotorua. S: Otago (Saddle Hill), Southland (Waihopai Scenic Reserve near Invercargill). Mainly northern in coastal forest with Pannaria elatior, Pseudocyphellaria aurata and P. episticta. On Cordyline australis, Avicennia resinifera, Beilschmiedia tawa, Leptospermum ericoides, Metrosideros excelsa and Olearia ilicifolia, rarely on andesite-conglomerate.

Australasian

In earlier acounts of New Zealand lichens this species (and also S. martinii), was recorded as S. variabilis Bory, a taxon originally described from Mauritius. Examination of topotype material of S. variabilis shows this species to be a highly dissected, narrow-lobed plant with flattened, lacerate- incised (but not truely isidiate or phyllidiate) margins and with no isidia developed on the upper surface of the lobes. S. squamata is best developed in northern coastal forest and is also known from a collection made by Dr H. Krog from Queensland. It is distinguished from S. martinii by its characteristic squamiform, imbricate isidia which are never white-pruinose, by the upper surface which is never minutely white-papillate or spotted and by the orange-yellow apothecia; the spores are also slightly longer.