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Family: NectriaceaeGenus: Thyronectria
Anamorph: not known.
Teleomorph: Ascomata perithecia, 300-380 µm diam., ± globose, lacking a neck, with an inconspicuous central ostiole, loosely aggregated on a basal stroma in clusters of (6-) 10-20. Ascomatal wall composed of 4-5 layers of thin-walled, golden brown, sometimes flattened textura angularis with cells 12-19 x 7-13 µm, with an inner layer composed of similarly shaped hyaline thinner-walled tissue, and covered except for the ostiolar region in a bright yellow scurfy layer that dissolves in lactic acid and goes bright orange in KOH. Interascal tissue of extended apical paraphyses, at least sometimes evanescent by maturity of the asci. Asci developing sequentially from a basal layer of amorphous very thin-walled cells, 96-115 x 9-13 µm, the width dependent on orientation of the ascospores, very thin-walled, short-stalked, the apex rounded and apparently without apical structures, 8-spored. Ascospores mostly arranged obliquely uniseriately, (13.5-) 15-16.5 x 8-9.5 µm, cylindric-ellipsoidal, both ends rounded, with (3-) 5 fairly thick transverse septa and a single, thinner longitudinal septum dividing most of the transverse segments, with the longitudinal walls not always exactly congruent and the outer transverse septa sometimes slightly oblique when the end cell may not be divided longitudinal, olive brown with the septa appearing darker, not constricted at the septa, smooth-walled, without a gelatinous sheath or appendages.