Alexanders (Smyrnium olusatrum) is a tallish plant from the Mediterranean that grows wild in parts of the UK, particularly on the coast. It's certainly prolific on the North Kent coast as seen above -near Whitstable- where it can be found along the foreshore and on lanes and verges further inland.
 S. olusatrum is said to have been introduced by the Romans as a pot herb so perhaps its presence here is a legacy of their arrival on this shoreline.