Kretzschmariella culmorum (Cooke) Y.-M. Ju & J. D. Rogers



Kretzschmariella culmorum (Cooke) Y.-M. Ju & J. D. Rogers, Mycotaxon 51: 242.

º Hypoxylon culmorum Cooke, Grevillea 7: 51. 1878.

= Kretzschmariella guaduae Vigas, Bragantia 4: 105. 1944.

? = Auerswaldia bambusicola Speg., Anal. Soc. Cient. Argent. 19: 246. 1885.

º Hypoxylon bambusicolum (Speg.) Speg., Anal. Soc. Cient. Argent. 26: 31. 1888.

Hypoxylon nummularioides Rehm var. microspora J. H. Miller, ined.

Stromata effused-pulvinate, orbicular to elliptical, usually containing multiple perithecia, gregarious, superficial (probably subcuticularly erumpent), 1-5 mm long x 1-4 mm broad x 0.2-0.4 mm thick; surface gray at first, becoming black, plane to slightly undulate; outer crust thin, black, carbonous; interperithecial tissue whitish, soft, becoming brownish, disintegrated when aged; tissue lacking below the perithecial layer.

Perithecia flattened-spherical, 0.2-0.3 mm diam x 0.1-0.2 mm high. Ostioles faintly papillate.

Asci eight-spored, cylindrical, uniseriate, short-stipitate, 90-100 m total length x 9.5-14 m broad, the spore-bearing part 84-93 m long, with apical ring bluing in Melzer's reagent, inverted hat-shaped, 3-4.5 m diam x 2.5-4 m high.

Ascospores brown to dark brown, unicellular, ellipsoid-inequilateral, smooth, with narrowly rounded ends, 13-17.5 x 5-7.5 m, with straight germ slit slightly less than spore-length to spore-length on the flattened side, usually bearing a cellular appendage on immature ascospores and sometimes on mature ascospores, with hyaline sheath closely appressed to the ascospore proper.