Caloplaca flavovirescens
≡Lichen flavovirescens Wulfen, Schr. Ges. Naturf. Fr. Berlin 8: 122 (1787).
Description : Thallus crustose, granular-scurfy, yellow-green to greyish white, often indistinct. Apothecia common, conspicuous, scattered to crowded, 0.1–1.0 mm diam., the discs convex, dark orange-brown. Epithecium yellow, granular, 8–12 μm thick. Hymenium colourless, 55–70 μm tall, without oil droplets. Paraphyses simple, 2 μm thick, apices swollen to 4 μm diam., not moniliform or branched. Asci clavate or cylindrical-clavate, 50–60 × 16–20 μm, 8-spored. Ascospores biseriate in ascus, broadly ellipsoidal (13–)15–16.5(–18.5) × 6.5–10 μm; septum 3–5 μm thick, ¼ to ⅓ length of spore.
Chemistry : Thallus and apothecia K+ violet-red; containing parietin.
S: Otago (Matanaka). Known also from Great Britain, Europe, Scandinavia, the Himalaya, North America, Australia (Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Scholz 2000; Brodo et al. 2001; Fletcher & Coppins 2001h; McCarthy 2003c, 2006; Nimis & Martellos 2003; Santesson et al. 2004).
Cosmopolitan
Illustrations : Wirth (1987: 99; 1995b: 215); Foucard (1990: pl. 72); Dobson (2000: 94; 2005: 103); Brodo et al. (2001: 201, fig. 166).
Caloplaca flavovirescens is characterised by: the saxicolous habit (basicolous, coastal rocks); the pale, grey-white, scurfy-granular thallus; crowded to dispersed apothecia, to 1 mm diam., the discs orange-brown; and broadly ellipsoidal ascospores, (13–)15–16.5(–18.5) × 6.5–10 μm; septum 3–5 μm thick, ¼ to ⅓ length of spore. Apothecia and thalli may be parasitised by * Muellerella lichenicola (q.v.).
