Leucostoma kunzei
Teleomorph: stromata 0.75-1.5 mm diam., ± circular, flattened at the base, rather prominent, breaking through the periderm in a lobate or transverse fissure. Ectostromatic disc 500-700 µm diam., dark greyish-brown. Entostroma delimited by a conspicuous black zone line, often visible in the peridermal fissure, containing 8-20 ascomata. Ascomata 300-400 µm diam., often angular by mutual pressure, densely crowded in the stroma, the peripheral perithecia sometimes arranged in two layers. Necks 100-130 µm diam., generally just penetrating the disc. Peridium 20-30 µm thick, thicker near the base of the neck, composed of olive-brown angular cells 8-13 x 2-4 µm in size. Ostiolar canal very narrow, ca 13-15 µm diam., periphysate. Asci 25-30 x ca 4 µm, narrowly clavate, sessile. Ascospores 5-7 x ca 1.5 µm, subcylindrical, slightly curved.
Not formally evaluated. Rarely reported, but potentially overlooked. Roy et al. (2012) consider that the species is introduced.
Similar to Leucostoma curreyi, but with a dark grey ectostromatic disc and smaller ascospores.
On twigs and small branches of Larix decidua.
There are records from Mull and Ulva (VC103 Mid Ebudes) and a very old one from VC32 Northamptonshire. There are probably further records of the anamorph, but their identity and links with the teleomorph need more examination.
Causes cankers, especially of trees that are stressed due to drought or following injury.