Kretzschmariella culmorum (Cooke) Y.M. Ju & J. D. Rogers, Mycotaxon 51: 242 (Fig. 72)
Basionym: Hypoxylon culmorum Cooke, Grevillea 7: 51. 1878.
= Kretzschmariella guaduae Vie ´gas, Bragantia 4: 105. 1944.
Index Fungorum number: IF 362245, Facesoffungi number: FoF 03399.
Saprobic mostly on bamboo and other woody substrates. Sexual morph: Stromata 1–4 × 1–4 × 0.2–0.5 mm, superficial, effused-pulvinate, orbicular to elliptical, becoming black, multiple ascomata per stroma, gregarious, plane to slightly undulate, outer crust thin, black, carbonaceous, interascomatal tissue brownish, soft, disintegrated when aged, tissue lacking below the ascomatal layer. Ascomata 200–300 × 100–200 μm, flattened, sphaerical. Ostioles papillate. Asci 90–100 × 9–13 μm, 8-spored, unitunicate, cylindrical, short-stipitate, easily dehiscent, J? apical ring bluing in Melzer’s reagent. Ascospores 13–18 × 5–8 μm, uniseriate, unicellular, ellipsoid-inequilateral, brown to dark brown, smooth, with narrowly rounded ends, with straight germ slit, spore length, hyaline, thin mucilagenous sheath present. Asexual morph: Based on Ju and Rogers (1994). Conidiophores scattered or aggregated into pustules, unbranched to dichotomously-branched, hyaline, smooth, slightly constricted at septa, 4–5 μm broad. Conidiogenous cells hyaline, smooth, terminal, indeterminate, with discoid conidial secession scars. Conidia produced holoblastically in sympodial sequence, pale brown, usually multicellular, beaked, cylindrical, with truncate base.
Material examined – BRAZIL, culm of Guadua, 2 Oct. 1935, Krug H.P., 1281, (W:holotype of Kretzschmariella guaduae); PHILIPPINES, Los Ban ˜os, on dead Bambusa blumeana Schult. & Schult. f. (Poaceae), 20 Aug. 1913, C. F. Baker (S-F44644, syntype).
Notes – Type material of Kretzschmariella culmorum is from Wand, and another authentic specimen from Sare is illustrated here. In both specimen’s asci were readily deliquescent and it was difficult to observe intact asci. However, a cluster of mature asci was observed. The asexual morph of K. culmorum is a special type of geniculosporium-like asexual morph with multicellular conidia and this gave rise to the retention of the genus in Xylariaceae.