An ascomycete has been puzzling me for the past few years. A habit photo and a squash preparation of an ascoma, stained with cotton blue, are attached. The fungus superficially has calicioid-like features such as urn shaped ascomata and spores that collect in a dry mass at the apex. I have sent photos to Drs. Steve Selva and Leif Tibell about it. They both suggested that it doesn't belong to any of the calicioid groups (e.g. Mycocaliciomycetidae) studied by lichenologists. I have searched a wide range of ascomycete literature trying to place this species.

It occurs on exudate of wounds of Prunus pensylvanica in PEI and NB Canada.

The ascomata are about 200-400 um tall and 150-200 um wide, and urceolate in shape. The walls are light brown and become melanized as it matures. Internally, the walls consist of linear, periclinally arranged hyphae. The asci are narrowly cylindric (c. 35 x 4 um), and lack an evident apical apparatus. They break down at maturity, producing a dry mass of spores that collects around the ostiole, and within the cavity in the upper part of the ascoma. Externally, the spore mass appears white to very pale yellow. The ascospores are uniseriately arranged, 8 per ascus, colourless, unornamented, and c. 3-4 x 2-3 um. They are ellipsoidal, but slightly compressed on the long axis.