Rinodina exigua (Ach.) Gray
* Account prepared by Dr H. Mayrhofer (Graz).
Lichen exiguus Ach., Lich. suec. Prodr.: 69 (1798).
Thallus thin or rarely evanescent, closely attached, pale or dark grey, continuous or cracked, smooth or rarely granular, without a perceptible prothallus, corticolous or lignicolous. Apothecia lecanorine, crowded or dispersed, sessile or ± innate, disc concave or plane, black, thalline margin concolorous with thallus, persistent. Hymenium 70-110 µm tall. Epihymenium brown or dark brown. Hypothecium colourless. Ascospores of Dirinaria -type, 12-20 × 6-9 µm. Chemistry: Cortex K- or + sordid yellowish. Atranorin.
N: North Auckland (Bay of Islands - J.D. Hooker). S: Canterbury (Waiau, Arundel). Nylander's reference [ Lich. N.Z.: 61 (1888)] to Lecanora exigua collected by Charles Knight from rock probably refers to Rinodina gennarii.
Cosmopolitan
