Flora of New Zealand Series

P. delisea (Fée ex Delise) D. Galloway et P. James, Lichenologist 12: 297 (1980).

Sticta delisea Fée ex Delise, Mém. Soc. linn. Calvados 2: 94 (1825).

Thallus orbicular to spreading, loosely to closely attached, 5-10(-15) cm diam. Lobes very variable, thick to delicate and thin or papery, ± rounded, undulate, contiguous to imbricate, margins variously incised, ± ascending, isidiate. Upper surface coriaceous, yellow-green, often browned or blackened, glossy, smooth, undulate or very shallowly ridged, isidiate, without soredia, maculae or pseudocyphellae. Isidia terete, small, simple, mainly marginal, occasionally laminal, rather delicate, often ± eroded at tips. Medulla white. Photobiont green. Lower surface tomentose to margins, apices or lobes with a narrow, glabrous zone, tomentum thick, felted, red-brown to blackish. Pseudocyphellae white, numerous, sunk in tomentum. Apothecia sparse to occasional, emergent, subpedicellate, marginal and laminal, disc red-brown to blackish, matt, ± shining, epruinose, to 5 mm wide, concave to plane, margins and thalline exciple pale tomentose, warted-corrugate. Ascospores brown, oblong-fusiform 1-3-septate, 20-30 × 7-11 µm. Chemistry: 7β-acetoxyhopan-22-ol, hopane-15α,22-diol, hopane-7β,22-diol (tr.), norstictic, constictic and stictic acids.

N: S: St: A: C: Ant: Sn: Throughout, lowland to alpine, on bark and twigs of forest trees and shrubs, and in open subalpine to alpine grasslands on rock and soil.

Austral

P. delisea is a very polymorphic species of wide distribution in the Southern Hemisphere occurring in Australia, Tasmania, New Zealand, the Subantarctic Islands and in South America. It is characterised by marginal, and sometimes also laminal, ± terete isidia, a shiny, glabrous upper surface of a yellowish-green colour, often cracked, eroded, browned or blackened in exposed habitats. Forms of this taxon comprise a continuum of individuals with thin, small lobes having heavily indented isidiate margins (called Sticta glabra and S. chloroleuca in earlier literature) to those with broad, thick lobes. The nomenclature of P. delisea has long been confused, with South American collections being widely identified as Sticta freycinetii, a larger species without isidia. The great diversity of form in P. delisea is not reflected in any chemical variation, but seems rather an adaptation to changing habitat conditions. The fertile counterpart species of P. delisea is P. homoeophylla, a New Zealand endemic.