Psiloglonium lineare
Anamorph: conidiomata pycnidial, 200-300 µm diam., often somewhat elongate, immersed in rotten wood and with a short erumpent papillate neck, fairly thin-walled, dark brown, composed of an outer layer of strongly pigmented thick-walled intertwined hyphae and an inner layer of paler small-celled angular tissue. Conidiophores formed in a well-developed palisade lining the entire inner surface of the wall, irregular in form, hyaline to pale brown, frequently branched. Conidiogenous cells formed as terminal and lateral branchlets, 4-9 x 1.5-2 µm ± cylindrical but often tapering towards the apex, proliferating sympodially with periclinal thickening, collarettes absent or inconspicuous. Conidia 3-5.5 x 1.5-2.5 µm, bacillar, ± hyaline, aseptate, thin- and smooth-walled, without a gelatinous sheath or appendages.
Teleomorph: ascostronata hysterothecia, 700-1500 (-3000) x 150-250 µm, linear, often confluent, usually in parallel series, at first narrow with a fine longitudinal fissure, later becoming broader with the black epithecium more or less exposed, with the flat stromatic top scarcely above the surface at maturity & the lateral walls poorly developed and less strongly pigmented below. Interascal tissue composed of pseudoparaphyses 1-1.5 µm diam., thin-walled below and somewhat thicker towards the apex, copiously branched & anastomosed above into a brown granular epithecium. Asci 75-95 x 11-13 µm, cylindrical to cylindric-clavate, with a short tapering stalk, thick-walled and fissitunicate, the apex rounded with a distinct ocular chamber, 8-spored. Ascospores mostly obliquely uniseriately arranged, 12.5-14 x 5.5-7 µm, clavate and strongly constricted at the ± median septum, the lower cell distinctly narrower than the upper cell, the apex rounded and the base obtuse, hyaline, thin- and smooth-walled, with granular contents, without a gelatinous sheath or appendages.
Not formally assessed. The species has a rather scattered distribution in GB&I, perhaps due to collecting effort. It would probably be considered as Data Deficient.
Distinguished especially by the highly elongated ascostromata that develop in parallel lines, and by the relatively broad ascospores.
Found on decorticated wood of a range of angiosperm trees, including Acer pseudoplatanus, Fagus sylvatica, Prunus spinosa and Ulmus sp. Presumably saprobic and evidently not host-specific.
Reported from England (VC1 W Cornwall, VC2 E Cornwall, VC36 Hereford, VC58 Cheshire, VC62 NE Yorkshire, VC64 MW Yorkshire), Wales (VC44 Carmarthen) and Scotland (VC103 Mid Ebudes, VC104 N Ebudes, VC108 W Sutherland).