Flora of New Zealand Series

Holotype: New Zealand. Southland, Mt Barber, above Deep Cove, Doubtful Sound, 1927. G. Einar & Greta Du Rietz 2063 : 2 – S.

Description : Flora (1985: 407).

Chemistry : Cortex K+ yellow-red; medulla K+ yellow-red, C−, KC+ red, Pd+ orange; containing salazinic acid.

S: Nelson (Denniston Plateau), Westland (Tuke River, Fox Glacier, Haast River), Otago (Huxley River, Matukituki Valley), Southland (Cascade Creek, Doubtful Sound). On acid rocks in high-rainfall areas close to the Main Divide in South I., associating with other species of Placopsis, including P. clavifera, P. elixii, P. hertelii, P. fuscidula, P. illita, P. perrugosa, P. polycarpa, P. rhodophthalma, and Gyalidea lecanorina, species of Porpidia, Stereocaulon colensoi and S. corticatulum.

Endemic

Illustrations : Lamb (1947: pl. XV, fig. 48); Malcolm & Galloway (1997: 105, 150); Malcolm & Malcolm (2000: 128); Australasian Lichenology 53 (2003: front & back covers).

Placopsis salazina is characterised by: the closely attached rosette-forming thallus; thick, rather shiny lobes; a usually single, rather large, central, spreading, rosette-shaped cephalodium; prominent, sessile apothecia, developing in concentric lines or arcs around central cephalodium; broadly ellipsoidal ascospores, 16.5–22 × 8–10(–11.5) μm; and the distinctive K+ blood-red medullary reaction (salazinic acid).