Choanatiara gracilis Nag Raj, in Nag Raj & DiCosmo, Can. J. Bot. 62(4): 712 (1984)
Saprobic on fruit capsules of Eucalyptus sp. (Myrtaceae). Sexual morph: undetermined. Asexual morph: Conidiomata 200–250 µm diam., 100–200 µm high, dark brown to black, pycnidial, solitary to gregarious, deeply immersed at beginning, then becoming partly erumpent at maturity, subglobose to broadly ellipsoidal, unilocular, thick-walled, glabrous, with a subcylindrical or narrow conical, lateral neck, ostiolate. Ostiole single, circular or oval, excentric. Conidiomatal wall 20–60 µm wide, composed of two distinct tissue layers, an outer layer of textura angularis to textura globulos with thick-walled, dark brown to brown cells, and an inner layer of textura prismatica with thick-walled, large hyaline cells but reduced in size towards the conidial hymenium. Conidiophores arising all around the cavity of the conidiomata, reduced to conidiogenous cells or present, when present, hyaline, broadly cylindrical, unbranched or sparsely branched, invested in mucus. Conidiogenous cells 5–7 × 2–2.5 µm, hyaline, enteroblastic, phialidic, ampulliform to lageniform, discrete or integrated, smooth-walled, proliferating once or twice. Conidia 12–17 × 2–3 µm (x = 15 × 1.8 µm; n = 30), hyaline, fusiform to occasionally naviculate, acute at apex, narrow and truncate at base, aseptate, smooth-walled, bearing a funnel-shaped, apical or subapical, mucoid appendage.
Material examined: India, Bangalore, Lalbagh Gardens, on fruit capsules of Eucalyptus sp. (Myrtaceae), 19 September 1980, T.R. Nag Raj (DAOM 186356, holotype).
Choanatiara gracilis (DAOM 186356, holotype) a, b Herbarium package and specimen. c Appearance of dark brown to black conidiomata on the host. d Vertical section of conidioma. e, f Section of peridium. g–i Conidiogenous cells and developing conidia. j–n Conidia examined using lactophenol cotton blue and India ink.(arrows show appendages). Scale bars d = 100 µm, e–f = 20 µm, g–i = 10 µm, j–n = 5 µm.
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