Byssoloma leucoblepharum
≡Lecidea leucoblephara Nyl., Annls Sci. nat. Bot. sér. 4, 19: 337 (1863).
Description : Thallus continuous grey to greenish grey, smooth to irregularly farinose, thin to thick (25–40 μm) and irregularly cracked, to 3 cm diam., bounded by a brown to black or bluish prothallus. Apothecia 0.3–0.5 mm diam., plane to subconvex, solitary to 2–3-together and distorted through mutual pressure; disc orange-brown to dark-brown with a bluish tinge, matt, epruinose, margins tomentose-arachnoid, whitish, yellow-white to yellow-grey. Hymenium 40–65 μm tall, colourless, Hypothecium pale- to dark-brown K− or K+ purplish brown. Ascospores bacillar to oblong, 3-septate, 10–18 × 2.5–4 μm. Conidia pyriform, 4–5 × 1.5–2 μm.
N: Auckland (Waitakere Ra.). On leaves of Beilschmiedia tawa. Widely distrbuted in tropical and subtropical regions (Santesson 1952; Santesson & Tibell 1988; Lücking 1992; Kalb & Vězda 1994b; Elix & McCarthy 1998; Lücking & Kalb 2001; Aptroot 2002e; Wolseley et al. 2002; McCarthy 2003c, 2006; Lücking et al. 2003; Nimis & Martellos 2003; Farkas 2004). Known also from southern England and from France where in deep ravines it colonises twigs and leaves of Buxus and bark of Corylus and Quercus (Sérusiaux 1989, 1992). Also in British Columbia (Aptroot 1996: 196) and Réunion (Rønhede et al. 2003).
Pantropical
Illustrations : Lücking (1992: 140, fig. 51B); Malcolm & Galloway (1997: 96, 145, 148); Malcolm & Malcolm (2001: 44).
Byssoloma leucoblepharum is characterised by: the foliicolous habit; the grey to greenish grey, irregularly farinose thallus; orange-brown to dark-brown plane to subconvex apothecia with a bluish tinge and tomentose-arachnoid margins; and 3-septate ascospores, 10–18 × 2.5–4 μm.
