Heterodermia speciosa (Wulfen) Trevis.
Trevisan, Atti Soc.ltal. Sci. Nat. 11: 614.1868
Previously : Heterodermia isidiophora (Vain.) D.D. Awasthi
D. Awasthi. Geophytology 3: 114. 1973.
Basionym: Anaptychia isidiophora Vainio, Cat. Welwitsch Afr. PI. 2: 409. 1901
Foliose, orbicular to irregular, adnate to loosely adnate, 2–4 cm wide, often coalescing to form colonies up to 15 cm wide
0.5–1.5 mm wide, plane to weakly convex, sublinear-elongate, often slightly broader towards the apices, dichotomously branched, ± discrete at the periphery, radiating; apices not ascending, eciliate, with distinct pseudocyphellae along the margins of the lobes or on small short lateral branches
Grayish white to gray to brownish gray, ± darker at the lobe tips, pruinose or not
Sorediate; soralia white to bluish gray, originating mostly from bursting pseudocyphellae, developing into subcapitate or labriform soralia
Lower Side :
Corticate, whitish to pale brown, rarely dark gray in the centre. Marginal rhizines frequent, concolorous with the thallus or becoming dark or black near the apices, irregularly branched, to 1 mm long, projecting beyond the lobes, lower surface rhizines sparse, mostly simple or sparsely branched
Rare, laminal, adnate to sessile, 1–3 mm wide; margin initially crenulate, later sorediate; disc concave, brown to brownblack, epruinose. Apothecia rare, laminal, sessile to substipitate, 3–8 mm wide; margin crenulate at first, subsequently sorediate; disc concave, brown to brown-black, epruinose
Pachysporaria-type, ellipsoidal, 25–37 × 14–18 μm. Pycnidia immersed or slightly protruding; conidia bacilliform, 4–5 × 1 μm
Cortex K+ yellow, C–, KC–, P+ yellow; medulla K+ yellow, C–, P– or P+ pale yellow; containing atranorin (major), zeorin (major), 6α-acetoxyhopane-16β,22-diol (minor), 6α-acetoxy-22-hydroxyhopane-25-oic acid (minor or trace), 6α-acetoxy-16β,22-dihydroxyhopane-25-oic acid (minor), leucotylin (trace)