Parmotrema perlatum (images of British lichens)

A relatively large, foliose species with smooth thallus, pearl-grey when dry, more greenish when damp, with very short, inconspicuous and often sparse, black, marginal cilia, underside black, with simple rhizines and a bare, tan-coloured zone towards the margin, soralia well delimited, marginal and apical; apothecia rare. Widespread, common in much of western and southern Britain; until recently largely absent from central and eastern England as a result of sulphur dioxide pollution, but now rapidly recolonising these areas as SO₂ levels have dropped.

Refs: Smith et al. (2009), 662; Purvis et al. (1992), 431 (as Parmelia); Dobson (2005), 310 (photo); Dobson (2011), 311-2 (photo); Allen (2007), 10, 16 & 37 (photos); Jahns (1983), 194-5 (photo, as Parmelia); Whelan (2011), 123 (photo); van Haluwyn et al. (2009), 100-1 (photo); van Herk & Aptroot (2004), 280-281 (photo, as P. chinense); Nordic Lichen Flora (2011) 4: 96, 164 (photo, printed too dark); Wirth (1995), 2: 673 (photo, as P. chinense); Wirth et al. (2004), 109 (photo, as P. chinense); Frahm et al. (2010), 127 (photo); Hinds & Hinds (2007), 352 (photo); Brodo et al. (2001), 493 (photo, as P. chinense); McCune & Geiser (2009), 233 (photo); Lichen Atlas of the British Isles 1: 1008 (1995) (as Parmelia).

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Images of British Lichens