What You Should Know
Pachyella clypeata is a small, reddish-brown cup fungus that can be recognized by its growth on rotting logs, its somewhat gelatinous texture, and how it clings tightly to its substrate. Found solitary or in small groups on water-soaked hardwood logs. Appears to be limited to eastern North America, but possibly more widely distributed.
Synonyms: Peziza clypeata, Discina clypeata.
Other names: Copper Penny.
Pachyella clypeata Mushroom Identification
Saprobic; growing alone or in small groups on rotting wood (primarily the wood of hardwoods) that is usually water-soaked; spring, summer, and fall; limited to eastern North America, but possibly widely distributed.
To 8 cm across but usually 2-4 cm across; cushion-shaped when young, soon becoming saucer-shaped or shaped like a flattened cup; broadly attached to the wood so that only the edges can be lifted away from the substrate; upper surface sticky when fresh, medium to dark brown, sometimes with a hint of red or purple, smooth or wrinkled, fading with age to tan; without a stem; flesh somewhat rubbery or gelatinous when fresh, sometimes becoming yellowish when torn.
Spores 18-25+ x 13-16 µ; smooth; elliptical; usually with 2 oil droplets. Asci with bluish tips (at least when young) in Melzer's reagent or IKI; 400-500 x 20-25 µ. Paraphyses cylindric with clavate or merely rounded apices; to about 10 µ wide; brownish in KOH, reddish-purple (when fresh) in Melzer's reagent. Excipular surface with many thread-like elements embedded in a gel, creating a palisade.
Photo 1 - Author: Richard Jacob (Creative Commons Attribution 4.0 International)