Occultitheca chiangraiensis (MFLU 24–0414, holotype) a host substrate b ascomata in host surface c, d horizontal and vertical section of ascoma e section through ascoma f peridium g ostiole h apical ring stained with melzer’s reagent i paraphyses j–m immature and mature asci n–r ascospores (r ascospores show mucilaginous sheath in indian ink) s a germinated spore t front and reverse view of the colony on PDA. Scale bars: 200 μm (b); 100 μm (c–e); 20 μm (f, g, i); 10 μm (h, n–s); 50 μm (j–m).