''Ephemera danica'' is a species of mayfly in the genus ''Ephemera''. The common name "green drake" is used in some parts of the British Isles for this species.
Specie identified by FraJH
This species is commonly found in clear water rivers and lakes with sandy or gravel bottoms throughout Europe and the British Isles. The life cycle is one or two years. ''E. danica'', with its markings and three tails, is the most commonly seen of British Ephemeridae.