Flora of New Zealand Series

≡Lecanora cerinella Nyl., Bull. Soc. Bot. Fr. 13: 370 (1966).

Description : Thallus minutely granular, whitish or pale greyish, often disappearing or obscured by rich development of apothecia, spreading in swards on flat bark or in irregular lines or small patches on young twigs, 1–5(–8) cm diam. Apothecia 0.05–0.3 mm diam., crowded, contiguous to hummocky, or forming closely interlocking patterns, round to contorted through mutual pressure, disc plane to shallowly convex, yellow to orange; thalline exciple absent; proper exciple persistent, pale yellowish, paler than disc; Epithecium yellow, 8–10 μm thick. Hymenium colourless 55–65 μm tall; paraphyses simple, 2 μm thick, apical cell swollen, to 4–5 μm diam. Asci cylindrical, 50–55 × 15–17 μm, (8–)10–16-spored. Ascospores broadly ellipsoidal to oval, 8.5–10(–12) × 5–7 μm; septum 5–6 μm thick, to ½ length of spore.

Chemistry : Thallus K−, apothecial disc K+ purple; containing parietin.

S: Otago (Alexandra, Roxburgh, Teviot, Evansdale Glen, Dunedin, East Taieri). On eutrophic bark of introduced shrubs and trees in parks and gardens (Daphne, Fraxinus, Juglans, Platanus, Populus, Salix, Sambucus). It is a distinctive, pioneer species on smooth bark and on young twigs (where it commonly occurs around bud scars and other declivities), associating with: Hyperphyscia adglutinata, Lecanora dispersa, Physcia adscendens, Rinodina pyrina and Xanthoria parietina. Probably much more widespread than records show. Known also from Great Britain, Scandinavia, Europe, North Africa, Turkey, Ukraine, India and Australia (Laundon 1992; Nimis 1993; Santesson 1993; Poelt & Hinteregger 1993; Egea 1996; John 1996; Kondratyuk et al. 1996a; Scholz 2000; Diederich & Sérusiaux 2000; Hafellner & Türk 2001; Llimona & Hladun 2001; McCarthy 2003c, 2006; Fletcher & Coppins 2001a; Nimis & Martellos 2003; Santesson et al. 2004).

?Cosmopolitan

Illustrations : Foucard (1990: 82); Dobson (2000: 89).

Caloplaca cerinella is characterised by: the corticolous habit; the closely grouped, minute apothecia (0.05–0.3 mm diam.); (8–)10–16-spored asci; and oval ascospores, 8.5–12 × 5–7 μm; septum 3–5 μm thick, ⅓ to ½ the length of the spore. Apothecial discs are sometimes parasitised by * Lichenodiplis lecanorae (q.v.).