Flora of New Zealand Series

Thallus dorsiventral, heteromerous, foliose-lobate, orbicular to spreading, often very large, loosely to closely attached, corticolous or saxicolous. Lobes broad, rounded, 10-30 mm wide, margins entire or variously incised or ornamented, ± ciliate. Upper surface smooth, shining or dull, plane, undulate or wrinkled, with or without, isidia, maculae, soredia. Upper cortex of palisade plectenchyma with a well-developed, pored epicortex. Medulla white. Photobiont green, Trebouxia. Lower surface black, with a characteristic brown or pale, marginal zone free of rhizines. Rhizines simple, unbranched, rather sparse, often coarse, central. Apothecia pedicellate, disc often perforate, thalline exciple smooth to wrinkled, sometimes maculate. Ascospores simple, colourless.

Parmotrema is a genus of large, foliose lichens included in the family Parmeliaceae Hale [ Phytologia 28: 334-339 (1974)], characterised by the ± broad, naked, marginal zone on the lower surface, and marginal cilia. The genus includes species formerly accommodated in Parmelia subgen. Amphigymnia Hale [ Contr. U.S. natn. Herb. 36 (5): 193-358 (1965); Krog and Swinscow Bull. Br. Mus. nat. Hist. (Bot.) 9 (3): 143-231 (1981)], and is best developed in tropical regions where over 110 species are known. In New Zealand 12 species are recorded, many of them being large, conspicuous plants common in lowland and coastal areas, with some species widely occurring on introduced trees (particularly fruit trees) and on fenceposts throughout the country. The large size and rich development of species of Parmotrema in coastal habitats in New Zealand led to several species (recorded in earlier accounts as Parmelia) being widely collected in the 19th century.