Apiognomonia petiolicola  

Ascomata 200-250 µm diam., spherical, black, numerous on petioles, neck straight 120-180 x ca 70 µm, central to lateral and emerging nearly level with the epidermis. Peridium ca 25 µm thick, of 3-5 layers of cells. Asci 39-47 x 6-8 µm. Ascospores 11-13.5 x ca 3 µm, sometimes slightly curved, septum dividing the spore 2:1, not constricted at the septum, the upper cell is the smaller, each cell usually 2-guttulate.