Acrocordiella omanensis sp. nov. (Requienellaceae, Xylariales) from the Sultanate of Oman Author Maharachchikumbura, Sajeewa S. N. Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P. O. Box 34, 123 Al-Khoud, Oman Author Hyde, Kevin D. Center of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Perera, Rekhani H. Center of Excellence in Fungal Research, and School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand Author Al-Sadi, Abdullah M. Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, P. O. Box 34, 123 Al-Khoud, Oman text Phytotaxa 2018 2018-02-16 338 3 294 300 http://dx.doi.org/10.11646/phytotaxa.338.3.7 journal article 10.11646/phytotaxa.338.3.7 1179-3163 13718756 Acrocordiella omanensis Maharachch., K.D. Hyde & Al-Sadi , sp. nov. Fig. 2 Index Fungorum Number : IF554043 Facesoffungi number : FoF 03886 Etymology: Named after the country where it was collected, Oman Saprobic on stems of Juniper plants. Sexual morph : Appearing as black spots on the substrate with black or white margins, sometimes with circular sunken perforation through the bark. Ascomata 745–810 μm high, 645–780 diam. (x = 780 × 720 μm), immersed, arranged singly or in small groups within the bark, sometimes surrounded by white mycelium, perithecial, globose to subglobose, black, ostiolate, with bell-shaped to cap-like, black clypeus around the ostiole. Ostiole periphysate. Peridium 40–70 μm thick, comprising brown to hyaline, multi-layered, thick-walled cells of textura angularis . Hamathecium comprising 2.3–3.8 μm (x = 3 μm) wide, long, numerous, aseptate, curved, scarcely branched paraphyses. Asci 238–275 × 15–18.5 μm (x = 260 × 16.5 μm), arising from basal and lateral cavity-surface of the ascoma, 8-spored, not clearly fissitunicate, cylindrical, unitunicate, with a short pedicel, simple or knob-like at the base, ascal apex thickened, containing a slightly refractive, inversely funnel-shaped dome, staining pale yellow in Lugol’s solution and faintly reddish in Congo Red (5.5–6.6 μm high, 5.6–6 μm wide). Ascospores 26.6–36 × 13–15 μm (x = 30 × 13.8 μm)., obliquely uniseriate, ellipsoid, inequilateral, narrowly rounded to nearly acute at the ends, 3-distoseptate, lumina rhomboid, median cells larger than terminal ones, multi-guttulate, at first hyaline, greyish olive when young, olivaceous to medium brown when mature, smooth and thick-walled, without a mucilaginous sheath. Asexual morph : Undetermined. Culture characters : Slow growing, reaching 4 cm within 15 days, whitish colonies. Material examined : Sultanate of Oman , Al Jabal al-Akhdar ( Green Mountain ), from dead barks of Juniper sp., 07.2016, SSN Maharachchikumbura OM17 (SQU H-100, holotype ), ex-type culture SQUCC 15091 ); ibid ., 03.2017, SSN Maharachchikumbura ( OM116 , paratype ), (culture SQUCC 13852 ) .