Flora of New Zealand Series

Holotype: New Zealand. South Auckland. Mt Maungatawhiri, Coromandel Peninsula, August 1974. B.W. and G.C. Hayward H44. 115, AK!

Thallus microphylline-squamulose, of small, stellately incised, subimbricate squamules (0.1-1 mm long and 0.1-0.5 mm wide) spreading in a ± diffract crust over a thin, blue-black prothallus, in irregular patches 3-5(-8) cm diam. Upper surface matt, smooth, pale grey-blue to glaucous brown, densely isidiate. Isidia pale blue-white, fingerlike at first, soon becoming coralloid-branched, delicate, friable, often dense and then ± obscuring thallus. Apothecia rare, round to irregular, sessile, concave to plane, 0.2-0.5 mm diam., disc matt, red-to dark-brown, proper margin pale, thalline margin irregularly crenulate, often isidiate, concolorous with thallus. Hymenium 100-200 µm tall, upper part red-brown, pigment non-granular, external to apices of paraphyses. Asci elongate-ellipsoid, 90-100 × 10-12 µm, with an I+ blue plug. Ascospores 8 per ascus, smooth-walled, 12-15 × 6-8 µm. Chemistry: TLC nil.

N: North Auckland (Radar Bush) to Wellington. S: Greymouth to Fiordland and Te Wae Wae Bay, mainly west of the Main Divide. St: C: An epiphyte of lowland and coastal trees and tree-ferms, in dense shade in humid habitats.

?Australasian

P. crenulata is characterised by its copiously developed, fragile, coralloid isidia and these and the microphylline squamulose thallus distinguish it from the two other isidiate species of Pannaria found in New Zealand (P. elatior Stirton and P. gemmascens Nyl.) both of which have markedly foliose thalli and simple isidia. It is discussed in Galloway et al. [ N.Z. J. Bot. 21: 101 (1983)].