Arthopyrenia cinereopruinosa
≡Verrucaria cinereopruinosa Schaer., Lich. Helv. Spicil. Sect. 6: 343 (1833).
=Arthopyrenia transposita Müll.Arg., Bull. Soc. Roy. Bot. Belg. 31 (2): 39 (1892).
Arthopyrenia transposita. Type: New Zealand. Sine loco [probably Wellington], Charles Knight – G (not seen).
Description : Thallus inconspicuous or slightly bleaching bark, non-lichenised. Perithecia (0.2–)0.3–0.45 × 0.2–0.3 mm, rounded to ellipsoidal, often covered by a thin layer of bark cells and appearing white-pruinose. Pseudoparaphyses 1–1.5 μm wide, persistent, slender, cells 8–16 μm long. Asci cylindrical-clavate, 55–75 × 10–18 μm. Ascospores clavate with rounded apices, 1-septate, strongly constricted at septum and each cell with a median constriction, 14.5–22 × 5–8 μm, with a distinct perispore.
N: Wellington. On smooth bark of introduced trees (Fraxinus, Corylus), still very poorly collected and understood in New Zealand. Known also from Great Britain, Scandinavia, Europe, Morocco, North America and Taiwan (Coppins 1988; Purvis et al. 1992; Nimis 1993; Santesson 1993; Harris 1995; Esslinger & Egan 1995; Egea 1996; Diederich & Sérusiaux 2000; Scholz 2000; Hafellner & Türk 2001; Llimona & Hladun 2001; Aptroot 2003a; Nimis & Martellos 2003; Santesson et al. 2004).
Cosmopolitan
Illustrations : Zschacke (1934: 142, fig. 63); Coppins (1988: 308, fig. 1C); Foucard 1992 (54, fig. 1B; 56, fig. 2D).
Arthopyrenia cinereopruinosa is characterised by: the corticolous habit; scattered rounded to ellipsoidal perithecia, often covered by a thin layer of bark cells and appearing white-pruinose; 1-septate ascospores, 14.5–22 × 5–8 μm, strongly constricted at septum, and each cell with a median constriction, and a distinct perispore present.
