Flora of New Zealand Series

Thallus foliose, lobate, heteromerous. Lobes rounded 0.3-1.5 cm broad, rarely sublinear, canaliculate, 0.2-0.3 cm broad, margins entire, often sinuous and ± ascending, without cilia. Upper surface uniformly grey, grey-green or ± olivaceous-grey, with or without isidia, with or without soralia, pseudocyphellate, pseudocyphellae, suborbicular, without a perforate, polysaccharide covering, scattered, not arranged in lines or in a ridged reticulum. Photobiont green, Trebouxia. Medulla white. Lower surface pale tan or whitish, brown or black, rhizinate. Rhizines simple, often not reaching lobe margins. Apothecia laminal or submarginal, disc entire, rarely perforate. Ascospores ellipsoid, colourless, simple, 8 per ascus, 10-27 × (5-)8-18 µm. Pycnidia laminal or rarely marginal. Conidia unciform, or filiform, or bifusiform.

Punctelia, a recent segregate of Parmelia sens. lat. , [Krog Nord. J. Bot. 2: 287-292 (1982)] is a cosmopolitan genus of 22 species, with centres of speciation in Africa, and in North and South America. Four* cosmopolitan species occur in New Zealand and are characteristic of urban and agricultural environments, being found on the bark of introduced trees and shrubs in parks and gardens (rarely on native trees) and on fenceposts and wooden gates in country areas. The major medullary compounds in Punctelia are the C+ orcinol depsides, lecanoric and gyrophoric acids together with various fatty acids. This chemistry differs markedly from that observed in Parmelia sens. str. , where the β-orcinol compounds salazinic and protocetraric acids are predominant.

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* Punctelia hypoleucites (Nyl.) Krog, is also present in New Zealand: see p. 353 under Parmelina subalbicans.