Flora of New Zealand Series

≡Collema australe Hook.f. & Taylor, Lond. J. Bot. 3: 656 (1844).

≡Collema saturninum var. australe (Hook.f. & Taylor) Hook.f., Fl. Ant. 2: 541 (1847).

Description : Thallus rather small, rosette-forming, loosely attached, 1–2 cm diam. Lobes 1–2(–5) mm wide, ±discrete at apices, complex–imbricate centrally. Margins thin, crisped, occasionally ±downrolled, entire to ±lobulate–pectinate. Upper surface blackish or grey-black when wet, dull lead-grey when dry, smooth or undulate, here and there minutely wrinkled (×10 lens), shining or matt, occasionally with minute, white pubescence (×10 lens) near margins and apices or scattered in patches on lamina, occasionally with small lobules developing along breaks or tears in thallus. Lower surface paler than upper surface, ±glabrous and smooth at margins, downy white-pubescent towards centre, pubescence very short, velvety (×10 lens), insertion of apothecia making prominent depressions. Apothecia laminal, widely scattered, rounded 0.1–1 mm diam., sessile to subpedicellate, pedicel concolorous with thallus or paler, occasionally minutely white-pubescent (×10 lens), disc plane or subconcave, matt, yellow-brown to red-brown, exciple distinct, entire, concolorous with disc or paler. Hypothecium densely interwoven, pale straw-yellow or brownish, ±opaque. Thecium 80–90 μm tall, colourless [Malme (1924b: 28) gives a hymenium height of 130–160 μm for Patagonian specimens]. Epithecium red-brown, 6.5–8.5 μm thick. Asci cylindrical, 65–85 × 10–12 μm. Ascospores broadly ellipsoidal, colourless to pale straw-yellow, apices pointed, with narrow apiculi (to 5 μm long) at one or both ends, submuriform, 5–6(–8) transverse septa and 2–3(–4) vertical septa, (35–)38–45(–50) × 10–12.5 μm [Malme (1924b: 28) gives 50–60 × 6.5–8.5(–9) μm, and Jørgensen (1975: 441) gives 40–50 × 8–10 μm for Patagonian specimens].

S: Southland (Supper Cove, Dusky Sound). On coastal rocks at high tide mark growing among mosses and other lichens, including Baeomyces heteromorphus, Bunodophoron spp., Cladonia spp., Dibaeis absoluta, Lobothallia radiosa, Mastodia tessellata, Physcia tribacoides, Placopsis cribellans, Psoroma melanizum, Stereocaulon colensoi, Verrucaria maura and Xanthoparmelia scabrosa – still very poorly known known in New Zealand. Known also from the W coast of Chile from Laguna San Rafael to Hermite I. (Galloway & Jørgensen 1995; Galloway & Knight 1999).

Austral

Leptogium australe is characterised by: the saxicolous habit; the minutely velvety white pubescence on the lower surface and on the upper surface at the lobe margins; the rather thin, overlapping or crisped lobes; and the prominent subpedicellate apothecia. The short, velvety pubescence on both upper and lower surfaces distinguishes this species from all other species of Leptogium. It also has the longest ascopores of any species in New Zealand. The combination of the above characters discriminates L. australe from the taxa L. malmei, L. menziesii and L. victorianum.