Flora of New Zealand Series

*P. opegraphoideum Christnach, Ertz, Diederich & Wedin in D. Ertz, C. Christnach, M. Wedin & P. Diederich, Biblthca Lichenol. 91: 81 (2005).

Holotype: New Zealand. South I., Southland, Longwood State Forest, 19 km NNW of Riverton, Purakino River Camp, along Granity Stream, 46º11's, 167º55'E, 150 m, on Pseudocyphellaria multifida, 1990, M. Wedin 2991 (UPS). Isotypes (BR, Herb. Diederich).

Description : Lichenicolous. Ascomata on upper surface of host thallus, rarely also on lower surface, solitary, black, rounded, gall-inducing; galls with a thalline pseudo-margin, not or slightly raised at maturity, sometimes ±crenulate or shortly isidiate, not or only slightly constricted at base, 0.7–2 mm diam.; ascoma surface ±plane, rarely slightly convex, typically lirellate, sometimes warted centrally, each wart corresponding to vertical projections of sterile tissue surrounded by hymenium; distinct digitations of lirellae often present at border of ascomata; not visibly damaging host. Stroma 150–280 μm thick; sterile stromatic tissues dark-brown to black, K+ olivaceous-brown, N+ reddish brown, generally well-developed between and below hymenium. Hymenium hyaline, I+ blue, quickly turning red, 100–125 μm tall. Subhymenium hyaline to pale-brown, 12–15 μm thick. Paraphyses richly branched, anastomosing, 1.5–3 μm thick, not swollen apically. Asci clavate, (4–)6-spored, 65–80 × 11.5–13.5 μm. Ascospores hyaline, 3-septate, not or only very slightly constricted at septa, the end cells often distinctly longer than central cells, (21–)22–27.5(–31) × (4–)4.5–5(–5.5) μm, perispore distinct, hyaline, 1–1.5 μm thick, becoming brown and granular when over-mature. Pycnidia immersed in stroma between loculi. Conidia bacilliform, hyaline, simple, 5–7 × 1–1.3 μm.

N: Gisborne (Lake Waikaremoana), Wellington (Tongariro National Park, Tararua Ra.). S: Nelson (E of Springs Junction); Westland (Alec's Knob); Southland (Lake Hauroko, Purakino River). On lichen epiphytes in forest, 150–1100 m.

Hosts : Pseudocyphellaria homoeophylla, P. multifida.

Illustrations : Ertz et al. (2005: 84, figs 62, 63; 85, fig. 64).

* Plectocarpon opegraphoideum is characterised by: ascomata that are lirellate at margins and warted centrally; ascospores that have elongate end cells; and Pseudocyphellaria homoeophylla and P. multifida as hosts.