Thyronectria quercicola  

Anamorph: conidiomata stromatic, formed singly or in small clusters on a basal stroma that later produces ascomata, 40–200 μm diam. and 60–150 μm high, irregularly subglobose, orange-brown to reddish, KOH+ slightly darker. Conidiomatal wall 12–25 μm thick, intergrading with the stroma, formed of elongate thin-walled prismatic cells. Conidiophores generally with 1(–3) branches, 15–25 μm long and 1–2 μm diam. Conidiogenous cells 7–95 × 0.8–1.3 μm, cylindrical to tapering, proliferating percurrently with a minute collarette and inconspicuous periclinal thickening. Intercalary phialides sometimes present, as short branches immediately below septa. Conidia (2.8–) 3.5–5 (–5.5) × (1–1.3 (–1.6) μm, slightly curved, hyaline, aseptate, smooth, without a gelatinous sheath or appendages.
Teleomorph: stromata erumpent through epidermis, ca 1 µm diam., rust to chestnut, KOH+ dark purple. Ascomata perithecia, superficial on well-developed stromata, scattered to aggregated in groups of 3–20, 250–400 μm diam., subglobose to globose, bright orange-red, cupulate upon drying, sometimes with a depressed apical region, apical region slightly darker, the upper part covered in yellow scurfy deposits. Ascomatal wall 40–70 μm thick, of two regions: outer region composed of globose to angular cells and the inner of elongate, thin-walled, hyaline cells. Interascal tissue of very thin-walled chains of swollen cells, constricted at the septa and evanescent at maturity. Asci 85–130 × 12–17 μm, narrowly to broadly clavate, short-stalked, thin-walled, with an inconspicuous iodine-negative ring at the apex, not blueing in iodine, 8-spored. Ascospores (26.5–) 31.5–44 (–48.5) × 2.5–4 (–4.5) μm, filiform to cylindrical, sometimes slightly curved, eventually 8–15 septate, hyaline, smooth, budding to produce hyaline, thin-walled, slightly curved, bacillar ascoconidia (3.5–) 4–5 (–5.5) × 1–1.5 (–2) μm in size, that completely fill the asci.