ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Cladoniaceae

Common name:            Summer Snow (see text)         

Synonyms:                    -

Habitat:                          Coastal (as text), grassland, heathland

Substrata:                      Well-drained mildly acidic soils

Growth forms:              Terricolous               

Basal thallus:                  Squamulose

Secondary thallus:        Podetia, small, with cups, but more often absent

Apothecia:                    Lecideine, very rare

BLS identity rating:        Graded 1/5 (identification should be straightforward)

Basal thallus forming compact mats, or separate small clusters, usually from 1-2cm high; comprised of comparatively large, elongate squamules, typically 4-10mm long to 3mm wide, but could be up to 25mm x 8mm; quite variable, but normally mostly erect or upturned, indented with deeply incised, slightly recurved apices showing the white tips of the underside; often with small tufts of dark brown to black marginal hairs; the upperside of the squamules are greyish-yellow to yellowish olive-green, and the underside white, although often with a pale creamy yellow tinge.

Podetia are often absent but, even when present, are hard to see; to 6mm tall, smooth, more or less evenly corticate, with small regular cups; apothecia very rare, brown, on cup rims; pycnidia dark brown, scattered on squamules.

During the summer months, when the thallus is dry, the tips of the squamules may completely roll over to more fully reveal the bright white undersides, giving the species the common name of Summer Snow from the Dutch name Zomersneeuw.  

Cladonia foliacea can be found throughout the British Isles, but predominantly in coastal locations growing in mildly acidic short vegetation, either on dunes or stabilised shingle coastal grasslands; far less frequently on inland sandy acidic grassland, or high quality, enriched, often disturbed heathland habitat, such as sites of old quarries or former military installations - typical of a few locations within the New Forest; and, albeit even more rarely, on grassy heathland hummocks. Less likely to be found on calcareous soil, where it is probably replaced by Cladonia convoluta; a very similar species with larger, less indented squamules.