Lichenoconium xylophila
Description : Thallus crustose, spreading, uniform, closely attached, moderately thin, smooth, continuous to verruculose or roughened, often appearing as a thin covering over the substratum, yellow-white to yellow-grey, without pruina or soredia. Prothallus absent. Apothecia sessile, 0.5–2 mm diam. Thalline margin concolorous with thallus, thin, smooth, flexuose, often crenate or scalloped. Disc plane to slightly convex, shiny, dark red-brown to somewhat blackish, intensely red-brown when moist, not pruinose. Amphithecium with small crystals, soon dissolving in K (campestris -type). Epithecium 10–15 μm thick, reddish brown, pigment not dissolving in K (glabrata -type). Asci clavate, 55–70 μm long. Ascospores ellipsoidal, 12.5–17 × 6.5–8.5 μm.
Chemistry : Thallus and apothecial margins: K+ yellow, C−, KC−, Pd+ yellowish; containing as major compounds: atranorin and an unidentified triterpenoid Lgr-1; and as minor compounds: chloroatranorin and an unidentified triterpenoid Lgr-2 (Lumbsch 1994: 100).
N: Northland (Onerahi, Leigh), South Auckland (Waikawau Bay Coromandel Peninsula, Rurima I.), Hawke's Bay. S: Marlborough (Kaikoura). On coastal driftwood logs, rarely on rocks. Ch: On fenceposts in open paddocks. Still rather poorly collected and understood here. Known also from North America where it ocurs along Pacific northwestern as well as eastern coasts (Brodo 1984a; Esslinger & Egan 1995; Brodo et al. 2001) and Japan (Lumbsch 1994).
?Cosmopolitan
Illustrations : Lumbsch (1994: 99, fig. 60A, B – as Lecanora grantii); Brodo et al. (2001: 390, fig. 437).
Lecanora xylophila is characterised by: the lignicolous habit (on maritime driftwood); the large, red-brown, campestris -type apothecia, usually with smooth and even margins; a whitish or yellow-white thallus. It was formerly known as Lecanora grantii H. Magn. (Brodo 1984a: 129–131; Lumbsch 1994: 100; Lumbsch & Feige 1996: 264–265).
