Aspidothelium cinerascens
Description : Thallus to 1 cm diam., continuous, rather smooth, greenish to greenish white or dark-grey, shining, 30–80 μm thick, cortical layer 10–12 μm thick. Prothallus bluish green to blackish. Perithecia sessile, white to pale- or dark-grey, the top darker than the sides, usually with a pure white disc-like or ring-like expansion (sometimes absent) 0.5–0.9 mm diam., a dark-grey to brown area around ostiole. Asci 140–160 × 24–30 μm. Ascospores 4, rarely 6, 2 or 8, muriform, with 12–18 transverse, and 4–6 longitudinal septa, ellipsoidal. 40–80 × 15–25 μm. Pycnidia globose, 0.1–0.15 mm diam., sessile or ±immersed, black. Pycnidial wall bluish. Conidiophores simple, straight, 10–12 × 1 μm. Conidia simple, oblong, slightly curved, 3–4 × 1 μm.
S: Marlborough (Pelorus Bridge). On small twigs of Coprosma rotundifolia (Malcolm & Vězda 1995b); Otago (Burke's Flat near Makarora) overgrowing hepatics on twigs (leg. J.M. Bannister). Widely distributed in the neotropics (Santesson 1952; Malcolm & Vězda 1995b; Herrera-Campos et al. 2004) and recently also recorded from Tasmania (McCarthy et al. 2001; McCarthy 2003c), and Argentina and Chile (Lücking et al. 2003).
Pantropical
Illustrations : Lücking (1992: 79, fig. 26D); Malcolm & Vězda (1995b: 14); Malcolm & Malcolm (2001: 35, 52).
Aspidothelium cinerascens is easily recognised by its distinctive whitish perithecia topped by an expanded white disc; and by its large (40–80 × 15–25 μm), muriform ascospores (Lücking 1992; Malcolm & Vězda 1995b).
