Flora of New Zealand Series

Description : Thallus pale-green, or pale to dark grey-green, often ±gelatinous when moist, of thinly scattered to densely aggregated ±globose goniocysts. Goniocysts 12–40(–60) μm diam., the outer hyphae often coated with a greenish K+ violet pigment. Photobiont cells 4–7 μm diam. Apothecia 0.1–0.4(–0.6) mm diam., shallow-convex to subglobose to tuberculate, whitish, pale- to dark-grey, brownish grey or blackish; true exciple poorly developed. Hymenium 25–50 m high; epithecium colourless or dull-greenish, K+ violet. Hypothecium colourless to dull-yellowish. Paraphyses 0.5–1 μm wide, expanded to 1.5 μm at apices. Asci 26–40(–50) × 8–12 μm. Ascospores ovoid–ellipsoidal to oblong, simple to 1(–3)-septate, 8–14(–17) × 2.3–4(–5) μm. Pycnidia white, or greyish around ostiole (due to greenish K+ violet pigment): (1) 50–120 μm diam., emergent to sessile, the ostiole often gaping, with ±cylindrical to narrowly obpyriform mesoconidia, (3.5–)4–6 × 1–1.5 μm; (2) 30–60(–100) μm diam., usually immersed, with cylindrical or narrowly fusiform microconidia, (5–)5.5–8 × 0.5– 1 μm.

Chemistry : Thallus K−, C−, KC−, Pd−; containing up to three unidentified compounds.

N: S: On bark, plant debris, soil, rotten stumps, soil in rock crevices, occasionally also on other lichens (Sticta filix, S. latifrons). Known also from Great Britain, Europe, the Azores, Canary Is, Scandinavia, North America, South America, Africa and Australia (Coppins 1983; Tønsberg 1992b; Esslinger & Egan 1995; Filson 1996; Galloway & Quilhot 1999; Brodo et al. 2001; Aptroot 2002e; Coppins 2002b; McCarthy 2003c, 2006; Nimis & Martellos 2003). The most common and variable species of the genus.

Cosmopolitan

Illustrations : Coppins (1983: 23, fig. 1D; 52, fig. 26; 53, fig. 27; 80, fig. 49A–D); Hertel & Rambold (1988: 295, fig. 1); Dobson (1992: 204; 2000: 234; 2005: 272); Kantvilas & Jarman (1999: 29); Boqueras (2000: 269, fig. 40C).

Micarea prasina is characterised by: the corticolous/terricolous habit; the pale- to dark-green thallus of densely aggregated goniocysts (gelatinous when moist); subglobose to tuberculate, whitish, greyish, to blackish apothecia, 0.1–0.4 mm diam.; oval–ellipsoidal to oblong, simple to 1-septate ascospores, 8–17 × 1–4 (–5) μm; and pycnidia producing mesoconidia and microconidia (see above).