Neokalmusia aquibrunnea J. Yang, Jian K. Liu & K.D. Hyde, sp. nov.

MycoBank number: MB 559449; Index Fungorum number: IF 559449; Facesoffungi number: FoF 12782;

Etymology: referring to the aquatic habitat of the fungus and brown ascospores.

Holotype: HKAS 112630

Saprobic on submerged decaying bamboo culms. Asexual morph: Undetermined. Sexual morph: Ascomata scattered or gregarious, erumpent, semi-immersed, perithecial, 190–290 μm high, 350–450 μm diam., conical or subglobose, dark brown, ostiolate, clypeus-like at surface view, with a small, papillate, pore-like opening at the centre. Ascomatal wall coriaceous, 27–50 μm thick, composed of host and fungal tissues, consisting of several layers of dark brown, polygonal, thick-walled cells of textura angularis, uneven thickness, thickened at the side of the base. Hamathecium composed of 1.6–4.3 µm wide, cylindrical, hyaline, septate, branched pseudoparaphyses. Asci 70–129 × 7–10.5 µm ( = 91.7 × 8.5 µm, n = 30), bitunicate, fissitunicate, clavate, 8-spored, with a small apical chamber and a long furcate pedicel. Ascospores 10–14 × 3–4.8 µm ( = 12.2 × 3.8 µm, n = 40), biseriate, narrowly fusiform with obtuse ends, gold brown to mid brown, uniseptate, smooth-walled, guttulate, constricted at septum, sometimes slightly curved, with broader upper cell and elongated lower cell.