Flora of New Zealand Series

≡Physcia domingensis f. isidiophora Nyl., Acta Soc. Sci. fenn. 7: 440 (1863).

Description : Thallus lobes slightly disjunct or adjacent, ±plane, not ascending, with short lateral lobes. Upper cortex of even thickness, isidiate. Isidia cylindrical, simple to coralloid–branched, marginal and laminal. Lower surface corticate, greyish to pale brown. Rhizines numerous, forming a dense, black mat. Apothecia when present sessile to subpedicellate, thalline exciple isidiate. Ascospores 21–31 × 12–17 μm, without sporoblastidia.

Chemistry : Atranorin and zeorin.

N: South Auckland (Whale I.). On rocks beneath semi-open Melicytus ramiflorus – Metrosideros excelsa coastal forest. Known also from East and South Africa, Madagascar, northern South America and E Australia (Kurokawa 1973; Aptroot 1987; Swinscow & Krog 1988; McCarthy 2003c, 2006; Moberg 2004b).

Pantropical

Illustrations : Kurokawa (1959b: pl. 2B – as Anaptychia isidiophora); Yoshimura (1974: pl. 3, fig. 6 – as Anaptychia isidiophora); Swinscow & Krog (1988: 95, fig. 43).

Heterodermia isidiophora is characterised by: the saxicolous habit; the laminal, simple to coralloid–branched isidia; the corticate lower surface with black rhizines.