Lecanora conizaeoides
Description : Thallus coarsely granular, thick, continuous olive-green to grey-green, spreading in patches 2–5 cm diam., commonly covered with coarsely granular, grey-green soredia. Apothecia uncommon, often obscured by mat of soredia, 0.4–1.2 mm diam. Thalline margin coarsely sorediate; disc pale grey-green to grey-brown, plane or subconcave. Epithecium colourless to pale yellow-brown. Hymenium colourless, (45–)55–70(–85) μm tall. Asci broadly clavate, 40–50 × 12–18 μm. Ascospores ellipsoidal, 10–14(–16) × 4–6(–7) μm.
Chemistry : Thallus K− or weakly yellowish, C−, KC−, Pd+ yellow→red; containing; fumarprotocetraric acid.
S: Canterbury (Christchurch), Otago (Dunedin). On bark of introduced trees, along roadsides and in parkland in heavily polluted areas (Johnson et al. 1998). This corticolous, toxitolerant lichen is widespread in the Northern Hemisphere (see Hawksworth et al. 1973: 356–359) in urban areas with high pollution levels. Colonies are commonly infected with the parasitic fungus * Athelia arachnoidea (q.v.), which causes pale brownish or whitish lesions, with felted, white margins. See Śliwa & Wetmore (2000). Dunedin material of this species collected from the bark of urban trees by Peter James in 1963 was thought to represent an introduction (Brightman 1964, 1965; Ahti 1965), and it may well be that the species is adventive here.
Cosmopolitan
Illustrations : Ozenda & Clauzade (1970: 582, fig. 480); Wirth (1987: 229; 1995b: 461); Phillips (1987: 168); Foucard (1990: fig. 137); Purvis (2000: 78); Dobson (2000: 191; 2005: 219).
Lecanora conizaeoides is characterised by: the corticolous habit; the dull-green, granular–scurfy, sorediate thallus, very rarely with apothecia; and containing fumarprotocetraric acid.
