Cladonia furcata (images of British lichens)

A variable species, with podetia grey-green to brown, branching ± dichotomously, forming loose, tufted to ± procumbent mats, finer branches generally erect, sharply pointed, cups never formed, podetial surface lacking soredia and with very few or no squamules, but with small, green areolar patches that may be set in the cortex surface or else raised to give a slightly granular appearance, podetia becoming deeper brown, smooth and glossy with age and exposure; pycnidia small, brown, on the branch tips, apothecia brown, in expanded clusters at the tips of podetia. In heathland, heathy turf, amongst rocks and on dunes, widespread and common, but easily overlooked amongst other Cladonia species.

Care is sometimes needed to separate C. furcata from the related C. rangiformis, but that species forms more richly branched, whitish-grey, erect tufts and has more conspicuous green areolar patches on the podetia. The two species often grow in close proximity on dunes, when the differences become readily apparent. C. furcata subsp. subrangiformis is a taxon of uncertain status, said to be browner and more prostrate, sparingly branched with lateral spinules, and with diagnostic, white nodules of calcium oxalate near the bases of the podetia (see Smith et al., 2009). It is rare and probably declining on chalk hills in southern England, doubtful and mostly erroneously recorded elsewhere.

Refs: Smith et al. (2009), 328; Purvis et al. (1992), 208; Dobson (2005), 138-9 (photo); Dobson (2011), 146 (photo); Britton (2008) 28 (photo); Allen (2007), 21 (photo); van Herk & Aptroot (2004), 142-143 (photo); Wirth (1995), 1: 308, 326 (photo, with apothecia); Wirth et al. (2004), 78 (photo); Holien & Tønsberg (2008), 88 (photo, unusually squamulose variant); Brodo et al. (2001), 255-256 (photos); Hinds & Hinds (2007), 184 (photo); Thomson (1967) 118-120, plate 16 (photo); Lichen Atlas of the British Isles 2: 389 (1996).

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Images of British Lichens