Pyrenomycetes Species Page

Chaetosphaeria tropicalis

Small clustered ascomata
F.A. Fernández & Huhndorf, Fungal Diversity 18: 40. 2005

Figure from EN5657, SMH1267, SMH1312, SMH2250
Complete Description
Ascomata ampulliform, dark brown with a gray luster, with a roughened surface, 194-271 µm diam., 236-295 µm high, superficial, occurring in dense clusters on abundant, subicular hyphae. Subiculum extensive, forming large and dense patches, hyphae dark brown to black, with brown multiseptate, sinuous, tubular or tapering setae, apically rounded, arising from the base of ascomata. Ascomatal wall of textura angularis to prismatica in surface view in water and in lactophenol, 11-14 µm thick in longitudinal section, composed of pseudoparenchymatic cells. Ascomatal apex papillate, short. Paraphyses sparse, simple, septate, 3.6-4.9 µm wide. Asci cylindro-clavate, short-stalked, 100-138 x 10-12.5 µm, with thin, refractive, apical ring, with eight biseriately arranged ascospores. Ascospores fusiform to cylindrical, with a slight distinctive curve, hyaline, sometimes very pale brown, three-septate, 19-26 x 3.2-6.3 µm. Anamorph: resembling Phaeostalagmus. Conidiophores semi-macronematous, dark brown. Phialides on CMA cylindrical to narrowly ampulliform, in terminal or lateral whorls, 7.8-17 x 1.9-2.5 µm at the base or up to 3.8 µm at midsection, tapering to 1.4-1.7 µm just below the collarette, collarettes small, cylindrical to funnel-shaped, 1-1.7 µm deep, 1.8-2.9 µm at opening. Conidia narrow oblong, hyaline, 5-8 x 1.2-1.5 µm on CMA. The cluster arrangement of the phialides disappears with repeated subculturing and is replaced by production of single, lateral phialides. For additional culture characteristics see Fernández and Huhndorf (2005).
Found on decaying wood and bark. Our collections are from Costa Rica, Jamaica and Puerto Rico. Figure from SMH1267, SMH1312 (Puerto Rico), SMH2250 and EN5657 (Costa Rica).
Similar Taxa Comments
Ascospores of Chaetosphaeria tropicalis are uniquely bent which distinguishes it from all other species. Another identifiable feature is the dense subiculum surrounding the clusters of ascomata. Chaetosphaeria tropicalis is also found in Thailand and it possibly has a pantropical distribution.