Thelotrema lepadinum (Ach.) Ach.
Lichen lepadinus Ach., Lich. suec. Prodr.: 30 (1798).
Thallus pale fawn, buff-yellowish or whitish or olive-greenish, in irregular patches 0.5-5.0(-10) cm diam., minutely granular-verrucose or wrinkled-plicate, matt or ± effuse-roughened, or ± continuous, with occasional cracks, very faintly and minutely white-maculate when wet (×10 lens). Apothecia frequent, prominent, hemispherical, 0.2-2.0 mm diam., sessile to ± constricted at base, or in ± dimpled warts, concolorous with thallus, margins thick, flattened or puckered, ± striate or wrinkled, pore gaping, prominent, 0.1-1.2 mm diam., exciple pale buff or whitish, lacerate-ragged, often obscuring disc, detached, producing a double-walled structure around disc, disc pale brown or pinkish to blackish or greyish. Ascospores colourless, long-ellipsoid or with tapering ends, 8-12 transverse septa, 2-5 longitudinal septa, (1-)2-4(-8) per ascus, 35-130 × 10-25 µm, straight or slightly curved. Chemistry: Cortex K+ reddish. TLC nil.
N: S: St: A: Throughout, and often ± common, on bark of forest trees (Carpodetus, Dacrycarpus, Dacrydium, Griselinia, Hoheria, Nothofagus), especially common on podocarp scales; from s.l. to 1000 m.
Cosmopolitan
The most frequently collected species of Thelotrema in New Zealand. It is discussed by Bailey and James [ Lichenologist 9: 175-179 (1977)].