Chlorociboria aeruginascens is a saprobic species of mushroom, commonly known as the green elfcup or the green wood cup because of its characteristic small, green, saucer-shaped fruit bodies. Although the actual fruit bodies are infrequently seen, the green staining of wood caused by the fungus is more prevalent. This species contains a quinone pigment called xylindein It is this compound that is responsible for the characteristic bluish-green stain of wood infected by this species, used today in decorative woodworking.The use of this wood, known as "green oak", goes back to 15th century Italy, where it was used in intarsia panels made by Fra Giovanni da Veroni.