Flora of New Zealand Series

Holotype: New Zealand. Canterbury, 9.5 km SSE of Arthur's Pass, Bealey Spur, along track to Grassmere Hut, 43º01's, 171º35'E, 800–1000 m, on decorticated stump of Nothofagus solandri var. cliffortioides, 17.xii.1980, L. Tibell 10085 – UPS. Isotype – CHR.

Description : Thallus parasitic on free-living algal crusts or parasymbiontic or parasitic on lichen thalli. Apothecia 0.7–1.1 mm tall, black with medium to rather long stalk. Capitulum lenticular to hemispherical, 0.18–0.30 mm diam. Epithecium reddish brown to brown. Hypothecium greenish brown to dark-brown, 90–110 μm thick. Exciple poorly developed, 8–10 μm thick of 3–4 layers of parallel hyphae formed as continuation of outer part of stalk, pale yellowish to greenish brown. Stalk 0.04–0.08 mm diam, of slightly intertwined, largely periclinally arranged narrow hyphae, 1–2 μm diam, outermost parts dark-brown, inner parts pale to greenish brown. Epithecium intensified reddish in K, stalk, exciple and hypothecium all yellowish brown. Asci 31–37 × 1.7–2.2 μm, cylindrical with thickened apex penetrated by a fine canal. Ascospores pale-brown, short cylindrical-ellipsoidal, 1-septate, 5–6 × 1.7–2.2 μm smooth; septum strikingly dark-brown.

N: Northland (near Warkwork, Waitakere Ra.), Gisborne (Mt Honokawa), Hawke's Bay (Black Birch Ra.), Wellington (Kaimanawa Forest Park, Whakapapa Village). S: Nelson (Tasman Mts), Canterbury (Hanmer, Arthur's Pass). On lignum of Nothofagus fusca. N. solandri and occasionally on Metrosideros robusta, 250–1150 m. Also known from Tasmania (Tibell 1987; McCarthy 2003c, 2006), Scandinavia, Britain and Central Europe (Tibell 1999c), Russia and Japan (Kashiwadani & Thor 2000; Tibell & Thor 2003; Hermansson & Pystina 2004).

Cosmopolitan

Illustrations : Tibell (1987: 133, fig. 96; 1999c: 86).

Chaenothecopsis nigra is characterised by: its small, smooth and pale spores with very dark septum. The stalk is often greenish (squash or section) and the epithecium usually distinctly reddish brown.