[1] Belonging to the phylum of fungus known as Ascomycetes (division Mycota) known as the sac fungi, they are characterized by a saclike structure, the ascus, which contains anything from four to eight ascospores in the sexual stage.

The sac fungi are separated into subgroups based on whether asci arise singly or are borne in one of several types of fruiting structures, or ascocarps, and on the method of discharge of the ascospores.

In maturity, the fruiting bodies can be 3–10 centimetres (1+1⁄4–4 inches) tall, externally colored black or brown,[3] sometimes with shades of blue or green.

[3] In springtime this fungus often produces a layer of white or bluish asexual spores called conidia, which grow on its surface and surrounding area.

[5] It is a common inhabitant of forest and woodland areas, usually growing from the bases of rotting or injured tree stumps and decaying wood.