Roccella phycopsis (images of British lichens)

Thallus fruticose, tufted and densely branched, the branches cylindrical and pointed, or narrowly flattened, dusky orange to lilac grey, grey when dry, developing clusters of conspicuous, subspherical, white soralia; apothecia with black discs but very rare. On sheltered, often overhung, vertical rockfaces on sea-cliffs, on old walls near the sea, and occasionally on dry tree trunks, very local and scarce on south and south-west coasts.

Refs: Smith et al. (2009), 826; Purvis et al. (1992), 553; Dobson (2005), 398-9 (photo); Dobson (2011), 402-3 (photo); Allen (2007), 19 (photo); Jahns (1983), 258-9 (photo); Wirth et al. (2004), 54 (photo); Valcárcel et al. (2003), 346-7 (photo).

The even rarer Roccella fuciformis is little branched and has pendent, broader (to 1.5 cm), strap-shaped branches. The soralia react (bright red) with sodium hypochlorite (bleach), cortex non-reactive, whereas in R. phycopsis the cortex tests positive (pink) but the soralia are non-reactive. However, these rare species should generally not be damaged or collected.

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Images of British Lichens