Pyrenomycetes Species Page

Chaetosphaeria conirostris

Small separate ascomata
Small clustered ascomata
F.A. Fernández & Huhndorf, Fungal Diversity 18: 22. 2005

Figure from SMH2183 (Costa Rica)
Complete Description
Ascomata ampulliform to obpyriform, dark brown, 208-230 µm diam., 240-270 µm high, superficial, occurring scattered with sparse setae on the substrate. Setae are brown, multiseptate, 185-245 x 6-7 µm, with a capitate apex, 4.5-8.5 x 7-11 µm, covered with a hyaline to dark yellow droplet. Ascomatal wall in surface view, opaque in water, textura angularis in lactophenol, 12-15 µm thick in longitudinal section, composed of pseudoparenchymatic cells. Ascomatal apex, conical, 63-71 x 69-71 µm at the base, tapering to 21.5-67.7 µm, papilla off-white, plectenchymatous. Paraphyses sparse, unbranched, septate, 4.2-4.7 (7.1) µm wide. Asci cylindrico-clavate, short-stalked, 95-120 x 11-13 µm, unitunicate, thin-walled, thin apical ring, with 8 ascospores irregularly arranged. Ascospores cylindrico-fusiform, hyaline, mostly one-septate, sometimes three-septate, 35.5-48.5 x 5.5-7.5 µm, inequilateral, straight to slightly curved. Anamorph: resembling Craspedodidymum Hol.-Jech., observed only in culture. Conidiophores absent or short, multiseptate, cylindrical, light brown. Phialides terminal, single, subhyaline to light brown, mostly clavate, 12.5-18 x 2.3-5.8 µm at the base, 5-7.8 at the widest point; collarette absent or, when present, hyaline, obconical, very-thin walled, 1.6-3.3 x 2.8-3.5 at the base, flaring to 3.8-5.5 at the apex. Proliferation of conidiogenous cells was not observed. Conidia hyaline, oblong to reniform, one-celled, 19.5-21.5 x 5.5-6.5 µm (a few conidia are limoniform, one-celled, 7-9 x 4.5 µm). For additional culture characteristics see Fernández and Huhndorf (2005).
Found on decorticated wood. Our collections are from Costa Rica and Ecuador. Figure from SMH2183 (Costa Rica).
Similar Taxa Comments
Chaetosphaeria conirostris has distinctive morphological features such as a conical ascomal beak and capitate setae bearing yellow-brown droplets. The ascospores are long, mostly one septate but sometimes becoming three septate. They are not as narrow as those found in other species with scolecosporous ascospores (e.g. C. spinosa, C. racborskii) but are comparable in width to the multiseptate C. chorotunicata and C. lignomollis. The anamorph in culture most resembles Craspedodidymum. Unfortunately, the anamorph of C. conirostris was not found on the natural substrate and comparisons to its manifestation in culture were not possible.