Physcia rugulosarium
≡*Microthelia rugulosaria Linds., Trans. Roy. Soc. Edinb. 25 (2): 540 (1869).
≡*Didymosphaeria rugulosaria (Linds.) Sacc. & Trotter in D. Saccardo, Syll. Fung. 22: 177 (1913). [For additional synonymy see Pegler et al. (1980: 513), and Hawksworth & Diederich (1988: 304)].
Description : Lichenicolous, pseudothecia immersed in apothecia of host, sometimes becoming slightly (to ¼) erumpent with age, scattered, arising singly, not connected by a clypeus, subglobose, ostiolate, coal-black, 75–100(–125) μm diam., pseudothecial wall pseudoparenchymatous ("textura angularis"), 5–10 μm thick of 2–6 layers of radially compressed golden-brown to dark-brown cells, periphyses absent. Pseudoparaphyses persistent, filiform, branched and anastomosing, septate and appearing knobbly, 3–4 μm thick. Asci elongate-clavate, usually markedly thickened medianly, often with a clear stalk, bitunicate, thick-walled, especially at apex which has an internal apical beak, I−, 6–80 × 17–20 μm, 8-spored. Ascospores irregularly biseriate in ascus, ellipsoidal to soleiform, apices rounded, constricted at septum, lower cell slightly smaller than upper, brown to dark-brown, faintly echinulate to smooth-walled, (10–)12–15(–16) × (4–)4.5–6(–6.5) μm.
N: Wellington (Wellington Harbour, S of airport). S: (Bruce Rocks). Parasitising apothecial discs of several maritime and inland species of Caloplaca.
Austral
Hosts : Caloplaca cerinella, C. cribrosa, C. circumlutosa, C. sublobulata. Known elsewhere on C. cirrhochroides, C. lucens, C. rugulosa, C. regalis (Lindsay 1869b; Pegler et al. 1980; Øvstedal & Hawksworth 1986; Øvstedal & Lewis Smith 2001).
Illustrations : Lindsay (1869b: pl. XXIII, fig. 32 – as Microthelia rugulosaria): Pegler et al. (1980: 513, fig. 4); Hawksworth & Diederich (1988: 296, fig. 1C).
* Polycoccum rugulosarium is characterised by: the lichenicolous habit (species of Caloplaca as host); the size of the perithecia; the shape of the ascus; and the size and shape of the ascospores.
