Phoma cytospora
≡*Phyllosticta cytospora Vouaux, Bull. trimest. Soc. mycol. Fr. 30 (2): 193 (1914).
Description : pycnidia, immersed, arising singly or more commonly in groups, scattered, black, subglobose, 40–80 μm diam., ostiolate; wall 2–3 layers of cells thick, mainly 7–10 μm diam., but to 15 μm near ostiole, brown to dark-brown, cells pseudoparenchymatous, not radially compressed, 5–7 μm long and 3–4 μm high, the inner cells subhyaline to pale-brown and with somewhat thinner walls. Conidiogenous cells arising from inner wall of pycnidium, lining pycnidial cavity, subglobose to broadly obpyriform, hyaline, smooth-walled, phialidic, not proliferating, 2–3 × 1–2 μm. Conidia abundant, narrowly ellipsoidal to subarcuate, one apex slightly truncated, hyaline, simple, sometimes 1–2-guttulate, smooth-walled, 5–7 × 1.5–2 μm.
N: South Auckland (N of Mamaku). S: Otago (Saddle Hill near Dunedin). Known also from Great Britain, Scandinavia, Europe, the United States and Australia (Vouaux: 1914a: 193; Hawksworth 1981; Hafellner 1993c; Kukwa 2002c; Diederich 2004i; Hawksworth & Cole 2004; Santesson et al. 2004; Dr S.Y. Kondratyuk, pers. comm.).
?Cosmopolitan
Host : Parmotrema perlatum. Elsewhere on a wide range of parmelioid lichens (on species of Flavoparmelia, Hypotrachyna. Melanelia, Menegazzia, Parmelia, Parmeliopsis, Parmotrema).
Illustration : Hawksworth (1981: 52, fig. 25)
* Phoma cytospora is characterised by: the lichenicolous habit; the black, globose, pycnidia immersed in the host tissue (Parmotrema perlatum); narrowly ellipsoidal to subarcuate, simple conidia, 5–7 × 1.5–2 μm, smooth-walled.
