ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Cladoniaceae

Genus Cladonia, meaning 'branch or twig-like' - specifically relating to these richly branched species

Common name:             Reindeer moss (see note)

Synonyms:                     Cladonia impexa

Habitat:                           Heathland, peat bogs, moors and dunes

Substrata:                       Acid soil, sometimes deadwood

Growth forms:               Terricolous, occasionally lignicolous                      

Basal thallus:                  Crustose, disappearing

Secondary thallus:         Podetia, richly branched

Apothecia:                     -  

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

Somewhat variable dependent on habitat; basal squamules absent; thallus loose, forming, often compact, delicately tufted, interwoven mats up to 100mm tall; often amongst and intermingled with heather or other low vegetation; sometimes extending and joining neighbouring colonies to cover large areas.

Podetia very richly branched with small, rounded heads; branching predominantly trichotomous at the apices, but with two branches developing sooner than the third such that it can give the appearance of splitting into two rather than three near the tips; axils often perforate; erect terminal branchlets generally spreading in all directions, albeit some may recurve, but not orientated one way; surface often roughened, areolate particularly towards the base.

Colour is light greenish-grey or pale cream, often with a yellowish-green tinge.

Apothecia very rare, minute and brown.

Cladonia portentosa is primarily found on lowland heath, peat bogs, upland moors and some coastal dunes, but is declining in many of those areas. It is also not uncommon on old fallen trees in open woodland. 

The widely used name of 'reindeer moss' is more of a generic term applied to a few superficially similar species that, in certain areas of the world, provide an important food source for reindeer (caribou). Whilst they have a somewhat moss-like appearance, they are obviously not a moss, so the name is sometimes switched to 'reindeer lichen'.