Pyrenomycetes Species Page

Chaetosphaeria cubensis

Small separate ascomata
Small clustered ascomata
Hol.-Jech., Mycotaxon 15: 278 (1982)

Figure from SMH3258, SMH4454 (Costa Rica)
Complete Description
Ascomata ampulliform, dark brown to black, 150-170 µm in diam., 160-180 µm high, separate, superficial on the substratum, papillate, with scattered conidiophores and setae on the ascomata and substrate, brown, multiseptate, tapering to a rounded or truncate apex. Ascomatal wall of textura angularis, 12-18 µm thick in longitudinal section, composed of brown pseudoparenchymatic cells. Ascomatal apex papillate, dark brown, shiny. Paraphyses sparse, unbranched, hyaline, septate. Asci cylindro-clavate, short-stalked, 60-80 x 7-9 µm, unitunicate, thin-walled, with 8 ascospores biseriately arranged, with a distinct apical ring. Ascospores fusiform, with rounded ends, hyaline, 12-20 x 3-5 µm, 3-septate, septa often indistinct. Anamorph: Catenularia on the substrate and in culture. Conidiophores single, multiseptate, light brown at the base, becoming darker brown and widening towards the apex. Phialides cylindrical to slightly obconical, brown, 18 -28 x 4.0-5.5 µm (at the widest point) 2.5-3 µm just below the collarette; collarette funnel shaped, 1.5-2.0 µm deep, 3.0-4.0 µm at the apex. Conidia one celled, hyaline when young, changing to light brown and finally dark brown, broadly obovoid or cuneiform, blunt at the base with a distinctive, refractive hilum, 6-8.5 x 3-5 µm at the widest point, 1.5-2 µm at the hilum, produced basipetally and successively forming chains. Setae are sometimes associated with conidiophores on the substrate.
Found on decaying wood. Our only collections are from Costa Rica. The type is from Cuba. Figure from SMH3258, SMH4454 (Costa Rica).
Similar Taxa Comments
Chaetosphaeria cubensis is closely related to C. catenularioides based on morphological and unpublished molecular data. Both species have Catenularia anamorphs that differ however in the size of their phialides and conidia. The ascospores also differ with those of C. cubensis smaller and less septate than those of C. catenularioides.