Buellia citrina H.Magn.
Holotype: New Zealand. Otago, Lake Harris saddle, on rocks in alpine grassland. G. Einar and Greta Du Rietz, 1927, S - not seen.
Thallus bright citrine yellow, areolate-cracked, areolae 0.4-0.8 mm wide and 0.35-0.5 mm thick, rounded to irregular, subconvex, separated by very thin cracks, and closely contiguous to ± dispersed. Apothecia rather sparse, solitary, immersed, 0.3-0.6 mm diam., brown-black, immarginate. Epithecium yellow-brown to 35 µm thick. Hypothecium pale, 50-75 µm thick. Paraphyses strongly conglutinate, apices clavate to 3.5 µm diam. Hymenium colourless 90-100 µm tall. Asci clavate, 75-85 × 20-25 µm. Ascospores 17-21 × 11-14 µm.
S: Otago, mountains close to Main Divide.
Endemic
