Flora of New Zealand Series

Thallus granular to verrucose or almost immersed, greenish-grey or with bluish tinge. Apothecia 0.4-1.6 mm high, epruinose or with a white pruina on lower side of capitulum, 4-8 times as high as width of stalk. Stalk and excipulum in watermounts I+ dark blue. Excipulum of densely intertwined, sclerotized hyphae with slightly elongated cells, laterally not reaching far above surface of hypothecium. Hypothecium blackish-brown with convex upper surface. Stalk black or with reddish-brown tinge, consisting of densely intertwined, sclerotized hyphae and sometimes with strands of interhyphal, granular crystals, outer part of stalk slightly paler and a very thin I-, gelatinous coat covers the stalk. Asci narrowly clavate, 21-32 × 4-5.5 µm with spores in part biseriate and overlapping. Ascospores remaining simple while enclosed in asci. Mature spores 1-septate, broadly ellipsoid to ellipsoid, 9-14 × 4-7.5 µm, with minutely verrucose to areolate ornamentation. Chemistry: No secondary substances identified. Thallus K-, C-, KC-, Pd- and UV-.

N: North Auckland, South Auckland, Gisborne, Hawke's Bay, Taranaki, Wellington. S: Nelson, Canterbury, Westland, Otago, Southland. Common on decorticated stumps of hardwoods and podocarps in humid and shaded situations but also not rare on bark of Metrosideros and Nothofagus, s.l. to 1050 m.

Cosmopolitan

C. subquercinum has a remarkably wide distribution occurring from the Northern Boreal Zone of the Northern Hemisphere through the subtropical Zone, and with a similar zonal distribution in the Southern Hemisphere. Primarily it requires high humidity but is very tolerant as to temperature.