Flora of New Zealand Series

Holotype: New Zealand. Gisborne. Urewera National Park, Lake Waikaremoana, along Ngamoko Track, 38º46's, 177º10'E, 940 m, on thallus of Pseudocyphellaria multifida, 1992, M. Wedin 4056 – UPS. Isotypes in Santesson, Fung. Lich. Exs. No. 153.

Description : Lichenicolous, parasitic on lichen hosts, producing necrotic patches up to 1 cm diam. Apothecia crowded, developing in uppermost cortex layers of host, soon becoming erumpent, rounded or irregular, solitary to confluent, 0.1–0.35 mm diam., pale orange-red (K+ intense purple), Epithecium 5–15 μm thick, yellowish to pale brownish. Hymenium 30–40 μm tall, yellowish, I+ red, K/I+ blue. Paraphysoids branched and anastomosing, 1–1.5(–2) μm diam., slightly enlarged (to 3 μm) at apices, without dark apical caps. Asci clavate to broadly clavate, 30–40 × 12–19 μm, 8-spored, without amyloid apical ring structures. Ascospores 1-septate, oblong-ovoid, colourless at first, becoming brown and verrucose when mature, 11.5–15 × 4–6.5 μm, slightly constricted at septum.

N: Gisborne (Lake Waikaremoana), Wellington (Tongariro Nat. Park, near Ohakune). S: Nelson (Mt Peel). Southland (Oblong Hill, Lake Hauroko; E of Milford Sound). St: (Ulva I.). In humid rainforest. Known also from Tasmania, New South Wales and Juan Fernandez (Wedin 1993; Grube et al. 1995; Wedin & Hafellner 1998).

Austral

Hosts : Pseudocyphellaria glabra, P. homoeophylla, P. multifida.

Illustrations : Wedin (1993b: 302, fig. 1; 303, fig. 2); Grube et al. (1995: 29, fig. 2A); Wedin & Hafellner (1998: 77, fig. 6C).

* Arthonia pseudocyphellariae is characterised by: the lichenicolous habit (on species of Pseudocyphellaria as host); the crowded orange-red apothecia (K+ intense violet); and the soleiform, brown, verrucose, 1-septate ascospores at maturity, 11.5–15 × 4–6.5 μm.