Peltigera malacea
An attractive and rare Dogtooth, the Links Dogtooth, found only in north east Scotland, mainly in acid dune systems. The upper surface is blue-green, tinged brown when dry, but deep olive-green wet with distinctive raised and undulate margins with vertical hair-like tomentum on the edges. The underside is felted with scarce rhizines.
Thallus 10–20 cm diam., rather thick, to ca 1.5 mm; lobes to 3 cm broad and 10 cm long, often imbricate; margins ± raised, undulate; upper surface ± even, downy or greasy, blue-green, tinged brown when dry, deep olive-green or brown when wet, smooth or often thinly scabrid-tomentose with erect hairs especially towards the lobe margins; lower surface pale at the margins, soon becoming brown-black, ± uniformly tomentose, veins and rhizines mostly absent, paler interstices few or absent. Apothecia round, appressed, brown-red, ± crenulate at the margin. Ascospores 55–70 × 5–6 µm, 3- to 5-septate, elongate-fusiform. Conidiomata unknown. Thallus with tenuiorin, methyl gyrophorate, ± gyrophoric acid (C+ red) and unidentified terpenoids (as in P. leucophlebia).
Distinguished by the continuous non-veined grey to dark brown felted underside, scarce rhizines and vertical, hair-like tomentum on the upper side, especially toward the margins.
In more acidic habitats than most Peltigera species. Mainly found in acid dunes and in conifer plantations on dunes. Rarely inland in habitats such as old gravel pits.
Rare, Scotland (primarily E. coast).
Probably climatically limited to the more sub-oceanic parts of Scotland; the species is common in the sub-oceanic parts of Scandinavia. Rare and dependant on disturbance of acid open habitats, especially in older parts of dune systems. Threatened by lack of disturbance, lack of grazing and vegetation succession in its main dune habitat. Relic populations in on afforested dunes (e.g. Culbin) require scrub/shrub control and occasional disturbance to maintain populations.
Britain: Endangered
Scotland: Priority Taxon for Biodiversity in Scotland
Cannon, P., Magain, N., Sérusiaux, E., Yahr, R., Coppins, B., Sanderson, N. & Simkin, J. (2021). Peltigerales: Peltigeraceae, including the genera Crocodia, Lobaria, Lobarina, Nephroma, Peltigera, Pseudocyphellaria, Ricasolia, Solorina and Sticta. Revisions of British and Irish Lichens 20: 1-34.
Text by Neil A Sanderson based on Cannon et al (2021)