Chaenotheca carthusiae (Harm.) Lettau
*Account prepared by Dr L. Tibell (Uppsala).
Calicium carthusiae Harm., Lichens de France 1: 186 (1905).
Thallus episubstratic, verrucose to minutely granular, greyish-green or green. Photobiont: Stichococcus or Trebouxia. Apothecia short to very long, 0.5-3.0 mm high, 5-39 times as high as width of stalk. Stalk 0.04-0.08 mm diam., shining, black but often with a granular, intensely yellow pruina. Capitulum broadly obovoid to lenticular. Excipulum 0.13-0.28 mm diam., Well-developed and obconical, or rather poorly-developed as a short collar around base of mazaedium, consisting of periclinally arranged, ± branched hyphae. Hypothecium broadly obconical to semiglobose, with convex upper surface. Capitulum with a dense yellow pruina on lower side of excipulum. Asci cylindrical, with well-developed stalk, 12-20 × 1.9-2.7 µm, produced singly and with uniseriate spores. Ascospores spherical to broadly ellipsoid, 3.1-7.7 × 2.5-3.6 µm, ± provided with irregular cracks giving rise to an irregular ornamentation. Chemistry: Thallus without secondary substances, K-, C-, KC-, Pd-. The yellow pruina of the apothecia consists of vulpinic acid.
N: North Auckland, South Auckland, Gisborne, Hawke's Bay, Wellington. S: Nelson, Canterbury, Otago, Southland. Common and equally frequent on trunks of various trees as decorticated stumps in shaded and rather humid situations, 60-1000 m.
Cosmopolitan
Most New Zealand specimens have conspicuously long (1.6-3.0 mm) and slender apothecia (height 31-62 times width of stalk) with small excipulum and smaller spores (2.5-3.3 µm) and asci than Northern Hemisphere populations. Rarely however, specimens very similar to those in the Northern Hemisphere are also found in New Zealand. Although the species in some areas was found with Trebouxia as photobiont [Tibell Lichenologist 14: 219-254 (1982)], in New Zealand, as in the cool parts of the Northern Hemisphere, Stichococcus only was found.
C. carthusiae has a very wide distribution in the Northern Boreal - Temperate Zones in the Northern Hemisphere.
