ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Cladoniaceae

Common name:             Heath Thorn Cladonia            

Synonyms:                     -

Habitat:                           Heathland, moors, bogs

Substrata:                       Dry or damp acid soil

Growth forms:               Terricolous

Basal thallus:                  Squamulose, absent or fast disappearing

Secondary thallus:         Podetia, pointed

Apothecia:                     Very rare

BLS identity rating:        Graded 1/5 (identification of this common form is straightforward)

Basal squamules absent or fast disappearing.

Podetia typically around 50mm tall; forming loose mats of spiky-looking tufts, sometimes spreading and intermingling with adjacent low vegetation or other lichen species, particularly the richly-branched varieties such as Cladonia portentosa; stems around 2-3mm dia., hollow and thin-walled, somewhat inflated; sparsely branched, diverging predominantly dichotomously, widening at the axils, which are mostly perforate.

Colour pale yellow-green to greyish-green, often brownish towards the abruptly pointing apices; corticate throughout; surface marbled in what is often described as a 'giraffe-skin' pattern.

Apothecia very rare; if present, brown, terminal and tiny.

Two variant forms of the species are recognised, ssp.biuncialis, and the much rarer ssp.uncialis, which is discussed on the following page.

The common and widespread variety ssp.biuncialis is characterised by its spiky, sharply pointed, entangled tufts and more of a dull yellowish-green colour; apothecia very rare. In damp, boggy situations, the podetia often become grossly inflated and somewhat irregular. On dry heathland, they're much narrower and more richly branched, diverging dichotomously (into two) towards the tips, although sometimes, particularly in more robust upright specimens, trichotomously (into three), or extremely rarely into four branches, but never into five.

This variety becomes very brittle when dry and easily broken, particularly alongside paths or in areas where cattle graze; if trampled, the podetia break into tubes that look like pieces of macaroni.

Footnote: after subsequently finding the rather splendid specimen featured in the final two photos, which clearly has branches diverging into not only five, but also into six smaller stems, giving the axils, what I understood to be the characteristic 'star-like' appearance of ssp.uncialis, I'm now starting to think that I've misinterpreted that part of the description (see the footnote on the following 'species account' for further information).