Microcalicium disseminatum (Ach.) Vain.
* Account prepared by Dr L. Tibell (Uppsala).
Cyphelium disseminatum Ach., K. Vet. Acad. Handl. 1817: 227 (1817).
Growing on species of Caliciales, free-living crusts of green algae and sometimes apparently saprophytic on bark and lignum having no association with living algae. Apothecia sessile to subsessile, short-cylindrical to obconical, 0.12-0.18 mm high, 0.13-0.25 mm wide, very variable in shape and size. Mazaedium often protruding as a column two or three times longer than width of apothecium. Paraphyses sclerotized, persisting in mazaedium. Excipulum in section aeruginose throughout. Outermost part sometimes reddish-brown, consisting of ± reticulately arranged, thick-walled cells. Asci when mature broadly ellipsoid to subclavate, 10-14 × 4.5-7 µm. Ascospores when mature (1-)3(-7)-septate, cylindrical, 11.3-14.2 × 3.2-4.0 µm, with ornamentation of spirally-arranged ridges, at maturity ± disrupted by irregular cracks. Pycnidia 0.04-0.06 mm diam. Conidia broadly ellipsoid, 2-3 × 2 µm. Chemistry: Apparently the same aeruginose pigment in the apothecia and spores as in other species of the genus, reacting K+ pale brown and reverting to intense green if excess acid is added. Structure of the pigment not known.
N: Gisborne, Wellington. S: Nelson, Westland, Southland. Rare and known only from a few collections. On decorticated stumps of Nothofagus and once on trunk of Libocedrus bidwillii in shaded and rather humid situations, 150-930 m.
Cosmopolitan
M. disseminatum is widely distributed in the Northern Hemisphere occurring from the Northern Boreal Zone to the Temperate Zone.
