Polycoccum crespoae
Description : Lichenicolous, immersed in upper cortex of host. Perithecia, immersed, minute, arising singly, in small patches of 10–25 separate perithecia, visible as minute black dots sprinkled over upper cortex, not forming galls. Perithecia subglobose to broadly ellipsoidal, (105–)115–135(–155) μm tall and (85–)11–120(–130) μm wide, dark-brown; ostiole (10–)25–35(–55) μm wide, not protruding above thallus surface, walls composed of 4–6 layers of angular and radially compressed, brown pseudoparenchymatous cells ("textura angularis"). Hamathecium of branched and anastomosing cellular pseudoparaphyses, abundant, persistent, 1.5–2 μm thick. Asci broadly clavate, short-stalked, bitunicate, with an internal apical beak, 44–64 × 12.5–13 μm, 4-spored, wall I−. Ascospores overlapping, uniseriate, deep yellow-brown, ellipsoidal to soleiform, 1-septate, the upper cell larger, the lower cell somewhat attentuated, constricted at septum, thick-walled, minutely warted, with a thin, enveloping sheath 1 μm thick, (14–)17–20(–21.5) × (6–)6.5–7.5(–8) μm (excluding sheath).
S: Otago (near Kurow, Alexandra Lookout, Flat Top Hill). In tussock grassland and in open depleted grasslands. Known also from Victoria, Australia (Váczi & Hawksworth 2001).
Australasian
Host : Xanthoparmelia semiviridis.
Illustrations : Váczi & Hawksworth (2002: 514, fig. 1; 515, fig. 2; 516, fig. 3A).
* Polycoccum crespoae is characterised by: the lichenicolous habit; the minute, black, closely to widely sprinkled perithecia visible as minute scattered black dots (×10 lens), flush with thallus surface; 4-spored asci; and yellow-brown, 1-septate soleiform ascospores, (14–)17–20(–21.5) × (6–)6.5–7.5(–8) μm (excluding sheath). It appears specific to its host, Xanthoparmelia semiviridis (where it appears to be most commonly developed on fertile specimens).
