TYPE. IRELAND. “On heath in large tufts; also on rocks, with apothecia on banks of Blackwater River, County of Kerry.” (Mackay 1836); Anonymous 3516 (US 00409570).
Description.Life form: lichenized fungus.
Thallus foliose, often forming extensive patches, to 15 cm diam., ± loosely attached; lobes sub-dichotomously to irregularly branched, to 8 mm wide (rarely wider), overlapping, with ± tightly sinuate axils; margins entire or ± indented, lobe ends ± down-turned. Upper surface whitish grey, fragile, with occasional, irregular, white, abraded areas caused by peeling of the fragile cortex. Vegetative diaspores absent (British & Irish material) or +/- sorediate, granular to schizidiate propagules originating on pustules or wrinkles (Switzerland, United States); lower surface black, dark brown near margins; rhizines richly dichotomously branched. Ascomata lecanorine apothecia, rare; thalline exciple coarsely crenulate, without rhizines. Ascospores 9-12 × 6-10 µm, almost spherical to shortly ellipsoid. Conidia 4-4.5 × 1 µm, bacilliform, with a small swelling near each end. Photobiont Trebouxia alga.
Substrate and Habitat. On acidic bark and rock in old forests as well as maritime habitats.
Distribution. Europe, Macaronesia, Neotropics to North America; in North Carolina found in the Blue Ridge ecoregion.
Note. This species was originally described as Parmelia rugosa, which was found to be an invalid name. The replacement name P. taylorensis was proposed by Mitchell (1961), which was later transferred to Hypotrachyna by Hale (1974).
Groner, U. & M. Dietrich (1996) Hypotrachyna taylorensis (Parmeliaceae) a European species in the New World. The Bryologist99(4): 457-459.
Hale, M.E., Jr O(1974) Delimitation of the lichen genus Hypotrachyna (Vainio) Hale. Phytologia28: 340-342.
Louwhoff, S.H.J.J. (2009) Hypotrachyna (Vain.) Hale 1974. Pp. 439-442 in Smith, C.W., A. Aptroot, B.J. Coppins, A. Fletcher, O.L. Gilbert, P.W. James & P.A. Wolseley (eds.). The Lichens of Great Britain and Ireland. The British Lichen Society, London.