Protopannaria pezizoides (images of British lichens)

Thallus a crust of minute, brown to grey squamules, grey-blue when wet; usually abundantly fertile, apothecia with orange-brown discs and conspicuous, whitish, granular margins, underside lacking hairs (compare Psoroma hypnorum). A local and generally upland species on peat, damp rocks and mossy trunks in the north and west.

Refs: Smith et al. (2009), 752; Purvis et al. (1992), 420 (as Pannaria); Dobson (2005), 365 (photo); Dobson (2011), 368-9 (photo); Jahns (1983), 232-3 (photo, as Pannaria); Whelan (2011), 135 (photo); Puntillo (1996), plate 28 (photo, as Pannaria); Wirth (1995), 2: 634, 635 (photo, as Pannaria); Moberg & Holmåson (1984), 166 (photo, as Pannaria); Holien & Tønsberg (2008), 111 (photo); Nordic Lichen Flora (2007) 3: 109, 203 (photo); Hansen & Andersen (1995), 105 (photo, as Pannaria); Brodo et al. (2001), 477-8 (photo, as Pannaria); Lichen Atlas of the British Isles 4: 979 (1999).

In addition to potential confusion with its close look-alike, Psoroma hypnorum, P. pezizoides is also closely resembled by Moelleropsis_nebulosa, which has a thallus of granules rather than minute, flattened squamules and generally smaller apothecia. Under wet, sodden conditions, confusion with Pannaria rubiginosa is also possible.

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Images of British Lichens