Flora of New Zealand Series

Holotype: New Zealand. Campbell I., cliffs and shingle feldmark at summit of Mt Fizeau, 505 m, 10.i.1970, H.A. Imshaug 46761 – MSC. Isotypes – CHR, HO, M.

Description : Thallus areolate, spreading irregularly, to 0.3 mm thick, pale-brown with ridges of carbonised material (dark-brown in section) giving thallus an overall dark-brown appearance. Areolae 0.2–0.5 mm diam. Prothallus absent. Medulla I+ violet. Apothecia black, lecideine, rounded, immersed in thallus, 0.4–0.5 mm diam., disc concave, pale-brown when moist, proper margin slightly raised, to 0.1 mm thick. Epithecium pale olive-brown, 15–20 μm thick (paler in K). Hymenium colourless, 70–85 μm tall, I+ blue. Paraphyses slender,1.5–2 μm thick, richly branched and anastomosing, not much swollen at apices and without a pigmented cap. Hypothecium colourless, 85–100 μm thick. Asci cylindrical-clavate, 50–60 × 17–20 μm. Ascospores colourless, simple, (11–)12–15(–18) × 6.5–8(–9) μm. Exciple massive, dark-brown, carbonised, cupular. Pycnidia not seen.

Chemistry : TLC−, all reactions negative.

A: (Hooker Hills, Adams I.). C: (Mt Honey, Mt Dumas, Mt Fizeau). On rock outcrops in subalpine fellfield, 435–570 m. Associating with Lecanora physcielloides, Lecidea lygomma, Lecidella sp., and Placopsis sp. (Fryday 2004a: 142).

Endemic

Rimularia maculata is characterised by: the saxicolous habit; the presence of dark ridges of carbonised material on its thallus; the I+ violet medulla; and the absence of secondary compounds.