ASCOMYCOTA | LECANOROMYCETES > PELTIGERALES > Peltigeraceae

Genus Peltigera, meaning 'carrying a light shield' - from the shape of the type apothecia but,

collectively, members of the genus are commonly referred to as Pelt Lichens.

Common name:            Field Dog-lichen

Synonyms:                    -

Habitat:                         Chalk grasslands, and other dry, well-lit locations

Substrata:                     Base-poor, stony, or base-rich sandy soils; mossy rocks

Growth form:                Terricolous (often amongst mosses)   

Thallus type:                  Foliose

Apothecia:                    Lecanorine, 'saddle-shaped'

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

Thallus large, up to 20cm across, variable, fragmented or rosette-forming; comprising lobes that are generally a fair bit longer than broad, up to 4cm long and 1cm wide, usually radiating, either contiguous or slightly overlapping, upturned with lightly crinkled or crisped even margins; appearing somewhat swollen and occasionally with adventitious (randomly formed and placed) lobules or small secondary lobes; mostly appressed

Upper surface thickly tomentose (leathery), especially towards the margins; sometimes slightly embossed.

Colour mostly greyish to reddish-brown, but highly variable according to hydration.

Underside with numerous, darkish, pronounced veins; white in the most part, although darkening towards the centre; not conspicuously hairy like some other species, and very occasionally somewhat scabrid.

Rhizines branched and often intertwined, coalescing at the base in small tufts, dark grey to blackish and longer towards the centre, smaller and whitish around the margins.

Frequently fertile with often large and conspicuous, wider than long, elevated and recurved, somewhat 'saddle-shaped' apothecia with in-rolled, coarsely crenulate or denticulate, uneven thalline margins; generally dark red-brown.

It could be confused with mature, fertile Peltigera didactyla, except that species is less leathery and has smaller 'finger-shaped' apothecia on narrow, entire, erect lobes. Also, similar in general appearance to Peltigera canina, although that species is typically darker in colour with a smoother upper surface, lacking the hoary feel.

Peltigera rufescens is said to be a common and widespread species, most frequently found in dry, warm, well-lit areas on base-poor, stony ground as well as base-rich silicate soils and mossy rocks; locally I believe it to be relatively common on chalk grasslands, but within the New Forest, only recoded from a couple of locations, one being the rough grass area at Blandford as previously noted.

NB. this 'species account' and accompanying photos will be regularly reviewed, refined and/or amended as further samples are found and inspected - I believe the details are correct, but I'm also mindful that, in some cases, the source information varies, even to the point of being slightly contradictory, so I want to ensure the page is as accurate as possible.