Flora of New Zealand Series

Holotype: New Zealand. Wellington, Ruahine Ra. on Nothofagus bark, W. Colenso 4548 – H-NYL 30829. Isotypes – BM, WELT [L1229].

Description : Flora (1985: 472–473).

Chemistry : TLC−, all reactions negative.

N: Wellington (Ruapehu, Ruahine Ra.). S: Nelson (St Arnaud Ra., Travers Valley), Canterbury (Boyle Rover, Arthur's Pass), Otago (Tautuku Bay).On Nothofagus bark and on coastal trees and shrubs.

Endemic

Psoroma coralloideum is characterised by: the corticolous habit; the squamulose thallus dispersed on a thin, black prothallus; squamules, flattened at margins, becoming congested, ascending and laciniate-coralloid centrally with apices lobulate and deflexed in a coralloid crust; cephalodia squamulose, crowded between thalline squamules, and often a dominant part of the biomass; apothecia plane to convoluted-irregular, 0.5–2.5 mm diam., the margins crenate-eroded, the disc chestnut-brown to red-brown, smooth, plane to undulate, with a wrinkled-corrugate to scabrid-areolate exciple; and ellipsoid ascospores, 15–21 × 8–10 μm. This species is very similar to Pannaria athroophyllum (q.v.), which is widely distributed in mainly lowland and coastal habitats in the South I. However, there is a distinct chemical difference between the two species. It is also closely related to Psoroma asperellum (q.v.).