Pyrenomycetes Species Page

Chaetosphaeria lapaziana

Large separate ascomata
Large clustered ascomata
phragmospore
(Carroll & Munk) Huhndorf & F.A. Fernández, Fungal Diversity 18: 48. 2005
Lasiosphaeria lapaziana Carroll & Munk
Sordariomycetidae
Chaetosphaeriales
Figure from Type GC87, SMH2182
Complete Description
Ascomata globose to ovoid, not collapsing, roughened, with reddish, russet or brown surface colour, (400-)500-950 µm diam., 525-825(-1025) µm high, superficial, occurring clustered on the substrate. Setae absent or only surrounding the ostiole, brown, stiff, pointed, short, 25-35 µm, sparse. Ascomatal wall of textura globosa in surface view; in longitudinal section uniformly 50-90(-145) µm thick; 2-layered, inner wall layer 10-30(-45) µm thick, composed of small, polygonal-to-elongate, pale-to-dark brown, pseudoparenchymatic cells, 4-6 cells thick, setae arising from this wall layer; outer wall layer 20-65(-115) µm thick, composed of variable-sized (largest range from 30-39 x 46-56 µm), isodiametric-to-polygonal, pale brown, pseudoparenchymatic cells, 5-20 cells thick, when fresh some of the cells contain pale purple pigment, disappearing when dried. Ascomatal apex somewhat papillate, conical, at times composed of apical setae 25-35 µm long; (50-)85-125 µm high, 25-45 µm wide at the apex, 65-150 µm wide at the base; circular ostiole 35-85 µm wide, with periphyses. Paraphyses 3-4 µm wide, numerous, septate, tapering towards apex. Asci cylindrical, short-stalked, 170-290 x 11-25 µm, with refractive apical ring, with eight, triseriately arranged ascospores. Ascospores fusiform to cylindrical to filiform, with apical end broadly rounded, basal end narrowly rounded, straight to slightly curved, hyaline, smooth, 7-septate, (45-)50-100(-120) x (3-)4.5-6(-7) µm. Anamorph: Craspedodidymum-like, seen only in culture. Conidiophores multi-celled, brown with simple phialidic conidiogenous cells; phialides clavate, 8-10 µm diam, 13-20 µm high, brown, collarette flared, rarely cup-shaped, 5-6.5 µm wide, 1-2 µm high. Conidia oblate to horizontally oblong, 10.5-12.5 x 20-28 µm, hyaline, one-celled, with short abscission scar or frill located medially on one long side; large and small guttules in the mature conidium; more than one conidium produced per phialide. For additional culture characteristics see Huhndorf and Fernández (2005).
Occurrence
Found on decaying wood. Our collections are from Costa Rica, French Guiana, Jamaica, and Puerto Rico.The type is from Costa Rica. Figure from Carroll 87 (holotype, NY) and SMH2182 (Costa Rica).
Similar Taxa Comments
Chaetosphaeria lapaziana shares the unique wall structure of C. raciborskii and C. rubicunda but generally tends to have larger ascomata than the others. As in C. rubicunda, in this species the setae, if present, are also concentrated only at the ascomal apex. However a number of specimens of C. lapaziana lack setae altogether. Chaetosphaeria lapaziana tends to have the widest ascospores reaching up to 6 µm in the Costa Rican type specimen, but the other collections have thinner, longer ascospores. Again the ascospores are seven septate, uniform among the species. In the anamorph, the formation of oblate to horizontally oblong conidia with a short abscission scar or frill located medially on one long side is distinctive but as with the other species the anamorph was not found on the substrate and only helpful in identification if the specimen is cultured.
Reference
Huhndorf and Fernandez