Flora of New Zealand Series

Thallus crustose, orbicular to spreading, closely attached, whitish-grey or dull greenish-grey, corticate, smooth to verrucose-areolate or granular, without a prothallus, corticolous or saxicolous. Photobiont green, Protococcus. Apothecia sessile, lecanorine, rounded, disc red or pinkish-red to orange, with or without pruina, thalline margin normally persistent, entire or crenulate, concolorous with the thallus. Ascospores transversely septate, colourless, 8 per ascus.

Haematomma is a cosmopolitan, temperate genus of c. 30 species included in the family Lecanoraceae. Both saxicolous and corticolous species are found. No monographic treatment is available but the papers of Culberson [ Bryologist 66: 224-236 (1963)], Asahina [ J. Jap. Bot. 39: 165-171, 209-215 (1964)], Thomson [ J. Jap. Bot. 43: 305-310 (1968)] and Rogers [ Lichenologist 14: 115-129 (1982)] provide useful information. Three species occur in New Zealand, one on rock, two on bark.