Buellia tetrapla
≡Lecidea tetrapla Nyl., Flora 69: 325 (1886).
≡Hafellia tetrapla (Nyl.) Pusswald in B. Marbach, Biblthca Lichenol. 74: 288 (2000).
Description : Thallus grey-white to olivaceous, thin, granular-uneven to smooth. Apothecia scattered, sessile, black, marginate, 0.5–0.8 mm diam. Hymenium colourless, inspersed with oil droplets; epithecium olive-brown. Asci 4-spored. Ascospores brown-black, 1-septate, with a thick septum and with apical thickenings (Callispora -type) and prominent ornamentation, (28–)32–42(–50) × 14–18(–22) μm.
Chemistry : Thallus K+ yellow; containing atranorin and diploicin.
S: Canterbury (Banks Peninsula, Devils Gap). On rocks near roadside. Known also from Brazil, Uruguay, South Africa, Réunion and Australia (Pusswald 1995; Marbach 2000; McCarthy 2003c, 2006) where it is often a corticolous species.
Pantropical
Illustration : Marbach (2000: 290, fig. 137).
Buellia tetrapla is characterised by: the saxicolous/corticolous habit; the grey-white thallus; the scattered, black, marginate apothecia; 4-spored asci; and ascospores with apical thickenings (Callispora -type), and prominent ornamentation, (28–)32–42(–50) × 14–18(–22) μm.
