Flora of New Zealand Series

Calicium xylonellum Ach. β trabinellum Ach., Meth. Lich.: 93 (1803).

Thallus immersed or rarely episubstratic, dark greyish-green, verrucose, very thin. Apothecia 0.5-0.9 mm high, with a yellow pruina on lower side of capitulum, 5-9 times as high as width of stalk. All parts of stalk I-. Capitulum lenticular to obovoid, 0.17-0.26 mm diam. Excipulum of isodiametric, to slightly elongated cells; cells of outer part pale, of inner, sclerotized and dark brown. Outer surface of excipulum with granular, yellow pruina. Hypothecium blackish-brown with convex upper surface. Stalk black, epruinose, 0.07-0.11 mm diam. Central part of stalk dark brown or with an aeruginose tinge, of intricately interwoven and heavily sclerotized hyphae. Outer part of stalk hyaline to brownish, 22-27 µm thick, of strongly gelatinized cells arranged as in the central part. The stalk is enclosed in a thin, gelatinous, I- coat. Asci cylindrical, 30-37 × 3.5-4.5 µm, with ornamentation of irregular cracks and short ridge fragments. Chemistry: The yellow pruina of the apothecia consists of vulpinic acid.

N: South Auckland, Gisborne, Wellington. S: Nelson, Marlborough, Canterbury, Otago, Southland. Not very common on decorticated stumps particularly of Nothofagus in moderately humid and shaded situations, 150-900 m.

Cosmopolitan

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