The Botryotrichum species are imperfect filamentous fungi belonging to the class Deuteromycetes. The perfect form belongs to the class Ascomycetes (Chaetomium). This genus contains about 7 phytopathogenic or nematophage species.
The dense colonies are white. The aleuspores rise directly from hyphae or on very short lateral branches. The hyaline, globular (10-25 mm in diameter) conidia, single or in groups, are slightly rough.
The Botryotrichum species are cosmopolitan and predominantly telluric, but also occur on plants, cellulose products, in wastewater, animal excrements, etc. Some species produce bioactive metabolites (botryolides AE, asterriquinones, descarestrin). Many species are parasites in eggs.