Pseudocyphellaria faveolata (Delise) Malme
Sticta faveolata Delise, Mém. Soc. linn. Calvados 2: 101 (1825).
Thallus ± orbicular to spreading, often forming extensive, entangled clones, loosely attached, to 25 cm diam., or larger. Lobes very variable ± rounded, irregular or linear-laciniate and ± subdichotomously branched, margins entire, often with raised, verruciform, white pseudocyphellae, apices blunt, notched or furcate, often complex-imbricate centrally, ± discrete at margins. Upper surface bright lettuce-green, olive-green to greenish- or yellowish-brown, sometimes superficially blackened, distinctly and regularly reticulate-faveolate, smooth, waxy, without soredia, isidia, phyllidia or pseudocyphellae. Photobiont green. Medulla white. Lower surface bullate, ridged, with a narrow, glabrous marginal zone at apices, ± densely and uniformly tomentose to margins in older lobes, tomentum felted, brown or black, rarely pale buff or whitish. Pseudocyphellae verruciform, raised above tomentum, with a conspicuous, inflated, smooth, fawn or buff, waxy margin, decorticate area flat, small, white or occasionally yellowish. Apothecia marginal and laminal, most commonly developed towards lobe apices, 2-5 mm diam., disc matt, black or dark reddish-brown, concave to convex, often white-pruinose when young, margins pale, whitish or greyish, prominent, inflexed at first, becoming denticulate and excluded with age, thalline exciple pale to red-brown, minutely verrucose-areolate, to white- or brown-tomentose. Ascospores brown, polaribilocular, fusiform-ellipsoid, (20-) 24-33 × 10-14 µm. Chemistry: Hopane-6α,7β,22-triol, methyl virensate, physciosporin, norstictic, constictic and stictic acids (Wilkins and James loc. cit., Code B).
N: S: St: A: C: Throughout, widespread and common on twigs and bark of trees and shrubs in forested areas and on successional vegetation, lowland and coastal to subalpine. A widespread, very polymorphic species.
Austral
P. faveolata is characterised by a green photobiont, variable lobes (broadly rounded to ± dichotomously branching), margins with ± prominent, raised, verruciform or conical white pseudocyphellae, marginal or laminal black apothecial discs which are often white-pruinose and a thick dark tomentum to the margins on the lower surface with raised, verruciform pseudocyphellae which are normally white but occasionally may be faintly yellow or creamish, the margins of which are swollen, smooth, fawnish and with a flat decorticate area. The chemistry is characteristic, containing physciosporin (Wilkins and James loc. cit., Code B). It is related chemically to P. granulata which is its sorediate counterpart species.
It is distinguished from P. carpoloma which has yellow pseudocyphellae and a different chemistry (Wilkins and James loc. cit., Code D), from P. rufovirescens which has a glabrous lower surface, white, fleck-like pseudocyphellae and red-brown apothecia and a differing chemistry (Wilkins and James loc. cit., Code A), and from P. billardieri by differences in lobe margins (in P. billardieri these are smooth and never with pseudocyphellae) apothecia (red-brown to black but never pruinose in P. billardieri) morphology of the pseudocyphellae and texture of the tomentum. The chemistry of P. billardieri also differs (Wilkins and James loc. cit., Code C) from P. faveolata.
The great variation in lobe morphology shown by P. faveolata, (possibly a response to differing ecological conditions, although there is no corresponding chemical variation) has resulted in an extensive synonymy [Galloway and James loc. cit., p. 298 (1980)] with the taxa Sticta cellulifera J.D. Hook. et Taylor, S. impressa J.D. Hook. et Taylor, S. physciospora Nyl., S. lorifera Stirton, and S. elatior Stirton being described between 1844 and 1900 for this polymorphic species. An excellent drawing (by Walter Fitch) of the round-lobed form (as Sticta faveolata var. cellulifera Church. Bab.) showing the deep faveolation, marginal, verruciform pseudocyphellae and the characteristic morphology of the pseudocyphellae of the lower surface with thick tomentum to margins, is given in Babington ( loc. cit., pl. CXXIV).
