Ramboldia stuartii
≡Lecidea stuarti Hampe, Linnaea 25: 709 (1852).
Description : Thallus immersed in bark, not apparent. Photobiont cells 10–12 μm diam., mainly near base of apothecia. Apothecia rounded or irregularly angular and deformed through mutual pressure, to 1.5 mm diam.; disc jet-black, glossy to matt, plane at first becoming undulate to convex with age; margins thin, flexuous, persistent, shining, concolorous with disc. Epithecium 8–12 μm thick, dark orange-brown to olive-brown, paler in K. Hymenium 32–50 μm, tall, pale orange-brown to olive-brown, darker in older fruits, ±colourless in K. Paraphyses conglutinate, sparsely branched, regularly tapered, apices not capitate. Hypothecium 60–80 μm thick, colourless to pale orange-brown, becoming colourless in K except for a central band which is K+ vivid-purple. Ascospores narrowly ellipsoidal, 7.5–12 × (2–)2.5–5 μm, usually with 1–3 plasma bridges. Pycnidia not seen.
Chemistry : Hypothamolic acid (Kantvilas & Elix 1994).
S: Nelson (Mt Arthur). On dead, decorticated wood of Libocedrus bidwillii in mixed subalpine forest (Dracophyllum, Libocedrus, Nothofagus) associating with Hypogymnia subphysodes, Pseudocyphellaria faveolatea, P. granulata (Kantvilas & Elix 1994: 301). Known also from Australia (Schneider 1980; Kantvilas & Elix 1994; McCarthy 2003c, 2006; Elix 2004b).
Australasian
Illustrations : Schneider (1980: 225, fig. 46 – as Lecidea stuarti; Kantvilas & Elix (1994: 300, figs 4, 6); Lumbsch et al. (2001: 31); Flora of Australia56A (2004: xvi, pl. 23).
Ramboldia stuartii is characterised by: the lignicolous habit; the endophloeodal thallus; abundant jet-black, plane, adnate apothecia; small, narrow, ellipsoidal ascospores; neatly tapered paraphyses; and the presence of hypothamolic acid, usually detected in microscope preparations by the K+purple reaction of a band of crystalline inclusions in the subhypothecium (Kantvilas & Elix 1994: 301).
