Anisomeridium biforme
≡Verrucaria biformis Borrer in W.J. Hooker & J. Sowerby, Engl. Bot. Suppl.: 1 (1831).
≡Acrocordia biformis (Borrer) Arnold, Flora 44: 537 (1861).
Description : Flora (1985: 3 – as Acrocordia biformis).
N: S: Throughout on introduced trees. Known also from Great Britain (Purvis et al. 1992), Europe, Scandinavia (Botnen & Tønsberg 1988; Santesson 1993; Nimis & Martellos 2003; Santesson et al. 2004), North America (Esslinger & Egan 1995; Aptroot 2002b), Central and South America, Asia, and Australia (McCarthy 2003c).
Cosmopolitan
Illustrations : Swinscow (1970: 229, fig. 4 – as Arthopyrenia biformis); Dobson (1992: 50; 2000: 57; 2005: 63); Boqueras (2000: 68, fig. 6).
Anisomeridium biforme is characterised by: the corticolous habit; the whitish, effuse, cracked to continuous thallus; scattered to crowded perithecia that are occasionally fused, hemispherical to subglobose, 0.25–0.5 mm diam., often leaving small pits; and ellipsoidal ascospores, with both cells equal and often with oil droplets, 12–16 × 5–7 μm. It is often confused with Acrocordia gemmata (q.v.), but this species has much larger perithecia and ascospores.
