Green Elfcup Chlorociboria aeruginascens (Nyl.) Kanouse ex C.S. Ramamurthi, Korf & L.R. Batra. syn Chlorosplenium aeruginascens (Nyl.) P. Karst. (illustrated 90% life size) Fruit body 1–5mm across, cup-shaped then flattened, attached to substrate by a short stalk, margin wavy, irregular; bright blue-green throughout. Spores 6–10×1.5–2¼, fusiform, containing 2 small oil drops at opposite ends of the spore. Asci 70×5¼. Habitat on fallen branches of deciduous trees, especially oak; mainly autumn although also found in spring to autumn. Very common. Not edible. The mycelium growing through the wood stains it conspicuously blue-green: this stained wood is often seen, but the fruit bodies are less frequent. The infected wood, known as ‘green oak’, was once much used in the manufacture of Tunbridge ware, in which woods of different colours were arranged into a pattern, compressed, then cut transversely into thin strips of veneer.