Flora of New Zealand Series

Lectotype: New Zealand. Otago, Horse Range, near Dunback, J.S. Thomson T1426 [2309] – CHR 379750. Isolectotype – OTA.

Description : Flora (1985: 48).

Chemistry : Thallus K−, C+ orange, KC−, Pd−; containing xanthones.

S: Canterbury (Waimakariri riverbed), Otago (Horse Ra., Macrae's Hill, Stoneburn, Waikouaiti Reservoir, Poolburn, Conroy's Dam, Lake Onslow, Leith Valley, Abbott's Hill), Southland (Tiwai Point). On dry, sunny exposed rocks in consolidated, grassy riverbeds, on schist outcrops in upland grasslands, on steeply sloping, shaded rocky banks, and on coastal quartz gravels. Associating with Buellia macularis, B. stellulata, Candelariella vitellina, Diploschistes gyrophoricus, Immersaria athroocarpa, Lecanora rupicola, Lecidea fuscoatrula, Ramboldia petraeoides, Rhizocarpon geographicum, R. distinctum, R. grande, R. lecanorinum, R. submodestum and species of Xanthoparmelia.

Endemic

Buellia dunedina is characterised by: the saxicolous habit; a rather friable, pale yellow-grey to yellowish olive areolate thallus (C+ orange) dispersed on a thin black prothallus visible between areolae and at margins; prominent, black, clustered convex apothecia; a brown-black epithecium; a carbonaceous hypothecium; oval-ellipsoidal to fabiform, greenish to olive-brown ascospores, slightly constricted at septum, 15.5–20.5 × 8–9 μm; and a C+ orange reaction (xanthones) of the upper cortex.