This is one of quite a few tall yellow composites which can easily be confused. At this time of year both Crepis capillaris (Smooth Hawk's-beard) and Crepis vesicaria (Beaked Hawk's-beard) are flowering. The seeds (achenes) need to be examined to be sure of a correct identification. The plants at this site were very healthy with some well over 1 metre tall.

Crepis biennis is common in England and fairly common in Ireland but parts of Wales and most of Scotland have very few sites.