Xylindein is a quinone pigment, a dimeric naphthoquinone derivative. It is produced by fungi in the genus Chlorociboria. This pigment causes green staining of wood infected by the fungi.
This pigment was first extracted in 1868 by Paul Thénard from wood. It resembled indigo, so he called it , from the combination of ' (wood) and ' (indigo) + '.