Green Elfcup
Chlorociboria aeruginascens
 
Description: 
Initially shaped like a goblet with a very short stem, the fruit bodies flatten with age and develop wavy edges. Individual fruit bodies are 0.5 to 1cm in diameter and usually less than 1cm tall. The upper, fertile surface is bright green and smooth, while the underside of the cup and the stipe are felty and pale blue-green, darkening with age.
Habitat: 
On bark-free dead wood, particularly oak, beech and hazel.
Additional Notes: 
The green stain is visible all the year round, but fruit bodies occur infrequently and mainly in autumn.