Chrysothrix candelaris (images of British lichens)

Thallus thin, leprose and granular-sorediate, sometimes diffuse, bright yellow; apothecia apparently unknown in Britain and rare elsewhere, minute, with orange but yellow pruinose discs (Smith et al. (2009)). Widespread and generally common on tree bark, occasionally on sheltered faces of siliceous rocks (but then compare Psilolechia lucida).

Refs: Smith et al. (2009), 308; Purvis et al. (1992), 187; Dobson (2005), 124 (photo); Dobson (2011), 132 (photo); Allen (2007), 40 (photo); Whelan (2011), 69 (photo); van Haluwyn et al. (2009), 146-7 (photo); Wirth (1995), 1: 291 (photo); Wirth et al. (2004), 306 (photo); van Herk & Aptroot (2004), 124-125 (photo); Moberg & Holmåson (1984), 220 (photo, as Lepraria candelaris); Puntillo (1996), plate 12 (photo); Brodo et al. (2001), 223 (photo).

Candelariella reflexa (page pending) can also form yellow sheets on trees, but it is more coarsely granular to minutely squamulose. Orange sheets on trees will usually be seen to be minutely filamentous under a lens and will most likely prove to be a species of the alga Trentepohlia. Caloplaca chrysodeta (page pending) is a more mustard yellow and is primarily a species of shaded, calcareous rocks and walls.

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Images of British Lichens