Thrinacospora Petr., Sydowia 2(1-6): 49 (1948)
Facesoffungi number: FoF 07711
Ascomycota, genera incertae sedis
Saprobic on dead leaves of Coriaria thymifolia (Coriariaceae). Sexual morph: undetermined. Asexual morph: Conidiomata pale brown, acervular, solitary to gregarious, semi-immersed, oval to circular or irregular, unilocular, glabrous, gelatinous. Ostiole absent, dehiscence by irregular breakdown of host tissue. Conidiomatal wall composed of thick-walled, pale brown to subhyaline cells of textura angularis. Conidiophores arising from inner layers of the basal stroma, hyaline, subcylindrical to irregular, branched, septate, invested in mucilage. Conidiogenous cells hyaline, enteroblastic, annellidic, cylindrical, integrated or discrete, indeterminate, smooth-walled. Conidia hyaline, cuneiform to cylindrical, truncate at the base, straight or bent, phragmosporous, 2-septate, apical cells with 2-4 short projections, smooth-walled, eguttulate (adapted from Morgan-Jones 1997).
Type species: Thrinacospora insignis Petr., Sydowia 2(1-6): 49 (1948)
Notes: Thrinacospora is a monotypic genus. Sutton (1980) described conidiogenous cells as holoblastic, discrete, determinate, forming a single apical conidium, while Nag Raj and DiCosmo (1982) described it as enteroblastic, annellidic, cylindrical, integrated. In this paper, the description and illustration are based on Nag Raj and DiCosmo (1982). Thrinacospora has conidia with several short protuberances at the apex, which is similar to Asteroconium and Tribolospora. However, the latter two genera have aseptate, star-like conidia, whereas Thrinacospora has 2-septate, cuneiform to cylindrical conidia (Sutton 1980, Nag Raj and DiCosmo 1982). Asteroconium possesses acervular conidiomata, holoblastic, monoblastic or sympodial conidiogenous cells with 1−2 sympodial or synchronously formed conidiogenous loci and tetrahedral to star-like conidia with much reduced lumina (Sutton 1980). While Tribolospora has pycnidial conidiomata, holoblastic conidiogenous cells without sympodial conidiogenous loci, and stellate conidia with up to 6 short protuberances (Nag Raj and DiCosmo 1982). There is no sequence data available for Thrinacospora. To clarify the taxonomy of these similar and closely related genera, fresh collections and phylogenetic inferences of types are needed.
Distribution: Ecuador (Sutton 1980).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.