Flora of New Zealand Series

Thallus immersed, sometimes visible as a greenish-grey tinge on substratum. Photobiont: Stichococcus. Apothecia short or long, 0.9-1.5 mm high, 15-30 times as high as width of stalk. Stalk 0.04-0.08 mm diam., usually with a thick, white pruina in upper part, lower part shining, black. Capitulum obconical, with well-developed excipulum; innermost, narrow part of excipulum consisting of periclinally arranged hyphae continuing into other part of stalk; much thicker outer part of excipulum consisting of swollen, anticlinally arranged hyphae 3-4 times as thick as hyphae of stalk. Excipulum 0.14-0.26 mm diam., with a thick, white pruina below. Asci short-cylindrical or irregular, with uniseriate or ± biseriate spores, 8-13 × 2.2-3.3 µm. Asci formed in chains. Ascospores spherical, 3.1-3.8 µm diam., smooth or with narrow, irregular cracks. Chemistry: Thallus K-, C-, KC-, Pd-. No secondary substances found.

N: Wellington. S: Canterbury, Otago. C. xyloxena seems to be rare in New Zealand, occurring on decorticated stumps of Nothofagus, 350-650 m.

Cosmopolitan

C. xyloxena has a wide distribution in the Northern Boreal - Temperate Zones in the Northern Hemisphere.