Collariella bostrychodes is a fungal decomposer of lignin and carbohydrate in the family Chaetomiaceae commonly found in soil and dung.

[1][2] The fungus is highly variable in shape and form, giving raise to the belief that there are two subclades in the species.

[9] The fungus was noted as being unable to produce functional antheridia, which suggested it wasn't part of the heterothallic species of Chaetomium.

[1] The genus, Collariella, was created to include for this diversity, its name refers to the dark collar-like apex that occurs around the ostiolar pore of the ascomata.

When young, C. bostrychodes appears as colourless and dextrinoid, but upon maturity, turns pale bluish grey or olivaceous with an apical germ pore .

C. bostrychodes often are darkened around the 25 to 35 μm wide ostiolar pore, giving the genus its name of Collariella.

[14][15] The filaments grow upward and inward to exert pressure against each other to create a central cavity which asci push their way up.

[3] The two subclades are divided by phylogenetic and morphological evidence, but high statistical support was found to suggest they share a recent common ancestor and are closely related.

[16] It can be isolated from soil, dung, decaying stems, roots, and seeds, but very rarely in woody materials.

[6] Oral and intraperitoneal administration of chaetochromin to mice may result in pronounced toxicity, which can lead to potential detrimental effects like selective inhibition of haematopoiesis.

[21] C. bostrychodes has been isolated from industrially polluted soils of the Kola Peninsula in ecosystems, specifically in ground cover and in areas of pine forests that have associations of moss shrubs and lichens shrubs, it believed to potentially cause diseases like Onychomycosis, skin infections, and peritonitis.