Amphisphaeria macrospora M. Niranjan and V.V. Sarma sp. nov. Figs. 1. a–m
Etymology – With reference to presence of larger ascospores.
Indexfungorum number: IF 558367.
Saprobic on an unidentified twig. Teleomorph: Stromata long thick stromata light green to grey, pseudostromata associated with the host at the base. Ascomata 630–700 × 1200–1300 µm, perithecial, multiloculate, conical shape fruit body within sub-globose, flat apex with central ostiolate opening, immersed to erumpent neck, 420 µm high. Peridium consists of loosely arranged parenchymatous tissue covered mostly with longitudinal cells. Hamathecium: paraphyses septate, unbranched, guttulate. Asci 162–212 × 11–17.5 µm ( = 179.2 × 14.9, n=10), uniseriate, 8-spored, overlapping uniseriate, irregular, with an apical ring and thickening, short pedicellate. Ascospores 19–22.5 × 6.2–9.5 µm ( = 19.87 × 6.87, n=12), hyaline, grey to brown, ellipsoidal, aseptate, rarely 1 or 2- septate, with broader or rounded ends, slight constricted at median septum, rarely with unequal septa, obtuse ends. Anamorph: Undetermined.
Material examined – India, Andaman and Nicobar Islands, South Andaman, Reserve Forest, Chidiya Tapu, (11˚29’33.7”N 92˚42’22.8”E). Recorded on decaying twig, 11 August, 2016, M. Niranjan & V.V. Sarma (PUFNI 16332). Additional specimens examined – Port Blair, Dollygunj, NIOT (11˚38’35” N 92˚42’42”E) on Calamus andamanicus (T294F1) 10 August, 2016; Chidiya Tapu, Viewpoint Area (11˚29’27” N 92˚42’36”E) on unidentified twig (T244F1) 08 January, 2017.
Notes − The morphological characters such as ascomata surrounded by a dark area, pseudostromata composed of host cells, bi-loculated, immersed in the host’s cortex; cylindrical, short pedicellate asci; 1-septate, brown ascospores are commonly present in Amphisphaeria (Maharachchikumbura et al. 2016). The new taxon A. macrospora has well-developed stromata, surrounded by black lining, erumpent ascostromata, cylindrical to oblong ascospores that are larger than the existing Amphisphaeria species. In the key to the Amphisphaeria, provided by Samarakoon et al. (2019), none of the terrestrial species have ascospores larger than 20 μm and hence we introduce a new species Amphisphaeria macrospora in the genus Amphisphaeria.
Figs 1. Amphisphaeria macrospora (PUFNI 16332) a, b Ascomata c Vertical section of Ascomata d, e Apical ring f Paraphyses g–j Asci k–m Ascospores. Scale bars c=100µm e, f–j=50 µm k, l= 20 µm I, m=10 µm.