Brown Cup Rutstroemia firma P. Karst. (illustrated 90% life size) Cup 0.5–1.5cm across, cup-shaped, expanding flattened and wavy, attached by a stalk 2–3mm long; inner surface ochraceous-brown, outer similarly coloured, becoming wrinkled. Spores 14–19×4–6.5¼, narrowly elliptical. Asci 150×8¼. Habitat on fallen oak branches; autumn to early winter. Occasional. Not edible.