Flora of New Zealand Series

≡*Tichothecium pygmaeum Körb., Denkschr. schles. Ges. vaterl. Cult 1853: 236 (1853).

Description : Lichenicolous on apothecia and upper surface of host. Perithecia (100–)150–250(–400) μm diam., superficial, globose, black, wall brown to red-brown, (20–)25–30 μm thick, of 2–8 cell layers, inner layers colourless, outer layers brown. Periphyses numerous, cellular, rarely branched, to 40 μm long and 1–3 μm thick. Asci clavate to subcylindrical, thick-walled, (30–)40–54(–80) × (11–)15–23 μm, with 20–32(–64) ascospores. Ascospores ovoid to ellipsoidal, dark-brown, thick-walled, (7.5–)8–10(–13) × (3.5–) 4–5(–6) μm. Pycnidia immersed, 45–90(–100) μm diam., wall (4–) 5–7(–8) μm thick, brown. Conidia colourless, (2.5–)3–5(–5.5) × (0.5–)1–1.5(–2) μm.

S: Canterbury (Mt Peel, Stew Point Rangitata River), Otago (Old Man Ra.). Known also from Great Britain, Europe, Scandinavia, Iceland, Svalbard, Greenland, Canary Is, Crete, the Ballkans, Greece, Asia, North America, South Georgia (Triebel 1989; Santesson 1993; Esslinger & Egan 1995; Cole & Hawksworth 2001; Triebel & Scholz 2001; Hawksworth 2003; Triebel & Kainz 2004).

Bipolar

Hosts : On Lecidea atromorio, L. lapicida (Triebel 1989: 166). On subalpine to high-alpine acid rocks. Elsewhere in its range it is a common alpine species known also from: Aspicilia calcarea, Bellemerea alpina, B. cinereorufescens, B. subcandida, Caloplaca anularis, C. biatorina, C. chalybaea, C. havaasii, C. proteus, C. trachyphylla, Lecidea atrobrunnea, L. confluens, L. fuscoatra, L. lactea, L. swartzioidea, L. leprosolimbata, L. leucothallina, L. silacea, L. speirodes, L. tessellata, L. verruca, and Xanthoria elegans (Triebel 1989: 162; Cole & Hawksworth 2001: 320).

Illustrations : Keissler (1930: 409, fig. 80 – as Tichothecium pygmaeum); Triebel (1989: 157, fig. 20B, C); Matzer (1993: 207, figs 4, 5).

* Muellerella pygmaea is characterised by: the lichenicolous habit; superficial apothecia, (0.15–)0.17–0.25(–0.35) mm diam.; asci with 16–64 ascospores; ascospores dark-brown, thick-walled, (7.5–)8–10(–13) × (3.5–)4–5(–6) μm