Flora of New Zealand Series

Thallus crustose, foliicolous, subcuticular ecorticate, effigurate or ± effuse. Photobiont green, species of Trentepohliaceae, probably Cephaleuros. Perithecia conical or convex, base immersed in the thallus. Paraphyses branched and anastomosing. Asci ± cylindrical, ± thin-walled at maturity. Spores 8 per ascus, 1- or 3-septate, ± fusiform, colourless. Pycnidia of two types, one with bacillar, 1-septate conidia, the other with simple, fusiform conidia.

Raciborskiella is closely related to Strigula, differing mainly in having branched and anastomosing paraphyses. Species of Raciborskiella are usually hypophyllous, occuring mainly near the margin of the lower surface of leaves; occasionally specimens (R. prasina) are found on the upper leaf surface. Two species both tropical, are described Santesson [ Symb. Bot. Upsal. 12: 194-199 (1952)], one of which occurs in New Zealand.