Stilbochaeta Réblová & Hern.-Restr., gen. nov.
MycoBank number: MB 842001; Index Fungorum number: IF 842001; Facesoffungi number: FoF;
Etymology: Stilbos (Greek) glistening, referring to slimy droplets of conidia that are glistening when fresh; chaeta (Greek) hair, bristle.
Type species: Stilbochaeta malaysiana (Kuthub.) Réblová & Hern.-Restr.
Description on the natural substrate: Colonies effuse, hairy, brown, composed of setae and conidiophores, occasionally ascomata, mycelium immersed or semi-immersed. Anamorph: Setae grow singly or in groups from stromatic cells or knots of hyphal cells, erect, straight or flexuous, septate, brown, paler toward the apex, unbranched, apex sterile, bluntly rounded, sometimes with a terminal or several lateral phialidic openings. Conidiophores macronematous, mononematous, single or grow in fascicles from stromatic cells or knots of hyphal cells around the base of the setae, erect, straight or flexuous to slightly undulating, unbranched, septate, smooth, brown, paler toward the apex. Conidiogenous cells integrated, terminal, mono- or polyphialidic, extending percurrently and sympodially, paler than the conidiophores; collarettes flared, funnel-shaped, often slightly stipitate or tubular near the base. Conidia falcate, oblong-falcate, ellipsoidal-fusiform, curved, tapering toward both ends, slightly truncate at the base, with an inconspicuous basal scar, 0–1(–3)-septate, hyaline, with a straight or gently curved setula at each end, setulae simple, bifid or trifid, inserted terminally at the apex and subterminally at the base, conidia accumulate in slimy fascicles. Teleomorph: Ascomata perithecial, non-stromatic, superficial, globose to subglobose, papillate, dark brown, setose; setae sterile, rounded at the apex. Ostiole periphysate. Ascomatal wall fragile, carbonaceous, two-layered. Paraphyses disappearing with age, septate, tapering, longer than the asci. Asci unitunicate, cylindrical-clavate, shortly-stipitate, apically rounded, ascal apex with a non-amyloid apical annulus. Ascospores fusiform, hyaline, transversely septate, without gelatinous sheath or appendages.
Habitat and geographical distribution: Members of Stilbochaeta occur in freshwater and terrestrial habitats, they are saprobes on leaf litter, bamboo and decaying bark and wood. They are widespread throughout the world, especially in tropical and temperate regions of Africa, Asia, Australasia, the Caribbean and South America ([2,17,19,28,29,31,81,180], this study).
Notes: – Stilbochaeta is introduced for a group of former Codinaea and Dictyochaeta species. It is morphologically and phylogenetically well-delimited and characterized by arrangement of setae and conidiophores in bundles growing from dark stromatic cells or knots of hyphal cells. Setae have sterile, bluntly rounded apices that are sometimes modified into mono- or polyphialides, while in Codinaea the setae are tapering toward the apices, which may be also fertile. The conidia are always septate, although aseptate and septate conidia can sometimes occur together in one strain, in contrast to morphologically similar Codinaea with exclusively aseptate conidia and setae. In culture, representatives of Stilbochaeta often form yellow, gold, cinnamon, or amber pigments that diffuse into the agar. The aerial mycelium that forms in vitro is often pigmented and the surface of the colonies is usually olivaceous cinnamon, olivaceous gold or beige-orange.
Species