Flora of New Zealand Series

Lectotype: New Zealand. Near Wellington, viii.1876, J. Buchanan – GLAM [fide Galloway (1985a: 11)].

Description : Flora (1985: 11).

N: S: Widespread on bark of rimu (Dacrydium cupressinum).

Endemic

Arthonia diaphora is characterised by: the corticolous habit; the pale whitish or creamish to greyish, minutely papillate, areolate, mosaic-forming thallus (arachnoid in parts) delimited by a fine black prothallus; scattered, rather sparse, brown-black to black, hemispherical and slightly rugose apothecia; 2-spored asci; and ellipsoidal, 1-septate, ascospores, 40–56 × 25–32 μm.