Ophiocordyceps thanathonensis Y.P. Xiao, T.C. Wen & K.D. Hyde, sp. nov., Index Fungorum number: IF 552731
Etymology: The specific epithet refers to Thanathon in north Thailand, the collection location
Holotype: MFLU 16–2908
Parasitic on ant (Hymenotera), collected from the underside of leaves litter. Sexual morph: Host 8–12 mm long, 4–6 mm wide, black ant without hyphae on the surface. Stromata 50–90 mm long, 0.5–3 mm diam, mostly single, stipitate, rarely double, arising from between the head and thorax of adult worker ants (Hymenotera), pale yellow to yellow. Stipe 40–90 mm long, 0.5–2 mm diam, clavate, with a fertile apex, becoming pale to yellow. Fertile head 0.8–1.3 mm wide, 2.5–3.2 mm diam, fusiform, yellow, upper surface roughened, lateral surface, ridged and furrowed. Ascomata 546–692 × 193–254 μm ( x̅ = 619 × 224 μm, n = 30), immersed, oblique flask-shaped, thick-walled. Peridium 12– 19 mm ( x̅ = 16 μm, n = 60) wide. Asci 369–496 × 5–7 μm ( x̅ = 432 × 6 μm, n = 60), 8-spored, hyaline, narrow cylindrical, with a thickened apex. Apical cap 5–6.6 × 5.5–7.5 μm ( = 6 × 6.5 μm, n = 60) thick, with a small channel in the center. Ascospores 365–490 × 1–2 μm ( = 428 × 1.5 μm, n = 60), easily breaking into part-spores, filiform. Secondary ascospores 5.1–6.4 × 1.6–2.0 μm ( = 5.7 × 1.8 μm, n = 90) fusiform to cylindrical, truncated at both ends, mostly curved, rarely straight, hyaline, smooth. Asexual morph: Undetermined.
Material examined: THAILAND, Chiang Rai. On dead ant (Hymenotera), 18 July 2015, Yuan-Pin Xiao, (MFLU
16–2908, holotype); (MFLU 16–2909, MFLU 16–2910, MFLU 16–2911, paratypes).
