Topeliopsis subdenticulata
≡Ocellularia subdenticulata Zahlbr. in C. Skottsberg, Nat. Hist Juan Fernandez 2 (11): 329 (1924).
≡Thelotrema subdenticulatum (Zahlbr.) G.Salisb., Lichenologist5 (3–4): 267 (1972).
Description : Thallus whitish, matt, of a single photobiont-hyphal layer, c. 25 μm thick. Apothecia Geaster -like, scattered, prominent, subspherical, 0.5–0.7 mm diam., with thick, cracked, exfoliating margins obscuring the disc apart from the central pore, 0.1–0.2 mm diam.. Secondary exciple yellow-red, c. 30 μm thick. Primary exciple colourless, attached, 25 μm thick, thickening towards epithecium. Periphyses 15 μm long. Hymenium 120–140 μm tall. Ascospores 8 per ascus, 2–3-seriate, colourless, oblong-fusiform, 16–26-septate, I+ purple, (60–)65–90(–120) × 8–18 μm.
Chemistry : TLC−, all reactions negative.
S: Canterbury (Hawdon Shelter, Waimakariri River), Otago (Maungatua). On bark of Nothofagus solandri var. cliffortioides, among mosses, in deep shade. Known also from Juan Fernandez and Australia (Zahlbruckner 1924; Salisbury 1972; Kantvilas & James 1991; Kantvilas et al. 1994; McCarthy 2003c).
Austral
Illustrations : Zahlbruckner (1924: tab. 24, fig. 6 – as Ocellularia subdenticulata); Salisbury (1972a: 267, fig. 4 – as Thelotrema subdenticulatum); Frisch & Kalb (2006: 38, fig. 1G).
Topeliopsis subdenticulata is characterised by: the corticolous habit; the prominent Geaster -like apothecia with thickened, splitting apothecial margins and a deeply urceolate, yellowish to yellow-brown, shining disc; transversely septate ascospores with 16–26 septa, 60–120 × 8–18 μm. Thelotrema decorticans (see above) is macrosopically indistinguishable, but has muriform ascospores.
