Pertusaria scutellifera
Description : Thallus whitish, areolate, surface irregularly subtuberculate and dull, without isidia or soredia. Apothecia disc-like, conspicuous, numerous and crowded, concolorous with thallus, 0.6–1.2 mm diam.; disc orange-brown, densely white-pruinose. Ascospores 1 per ascus, ellipsoidal, smooth, (125–)150–185 × 45–55 μm; wall 3–5 μm thick.
Chemistry : K+ yellow, C−, KC−, Pd+ yellow; containing thamnolic acid (Archer & Elix 1994a: 208).
N: Wellington (Mt Ruapehu, Rangataiki, Waipakahi Valley). S: Nelson (Mt Arthur), Canterbury (Arthur's Pass), Otago (Rees Valley, Dart Valley), Southland (Cascade Creek, Eglington Valley, Manapouri, Alton Valley near Tuatapere). On twigs of Dracophyllum uniflorum and bark of D. traversii, Nothofagus menziesii, and N. solandri var. cliffortioides. Associating with Haematomma hilare, H. nothofagi, Miltidea ceroplasta, Tephromela atra and species of Usnea.
Endemic
Illustrations : Archer & Elix (1994a: 205, fig. 6); Malcolm & Galloway (1997: 143, 165).
Pertusaria scutellifera is characterised by: the corticolous habit; disc-like apothecia; 1-spored asci; and the presence of thamnolic acid. It is distinguished from P. novaezelandiae by the chemistry (P. novaezelandiae contains hypothamnolic acid which reacts K+ purple-violet).
