Group of Fungi: Cup Fungi

Family: Helotiaceae

Latin Name: Chlorociboria aeruginascens (Nyl.) Kanouse ex C.S. Ramamurthi, Korf & L.R. Batra

Synonym(s): Chlorosplenium aeruginascens (Nyl.) P. Karst

Common Name: Green Stain of Wood

Description: Cup-shaped structure, 1/8–1/12 in (0.3–1.3 cm) across, becoming flattened in age, base narrowing to form a short stalk, bright green to blue-green, upper surface smooth, lower surface somewhat roughened; spores essentially colorless in mass.

Biological Role: Decomposer of wood.

Habitat: Commonly occurring in small clusters on decorticated (without bark) logs or stumps of broadleaf trees.

Geographical Distribution: Found throughout North America.

Comments: The most unusual feature of this fungus (and the source of the common name) is that the presence of the vegetative body (mycelium) in decaying wood causes the latter to turn green in color. The fruiting bodies are encountered much less often than green-stained wood containing the mycelium.