Great Willowherb (Epilobium hirsutum)  with a bit of Himalayan Balsam in the foreground and the weir in the lower reaches of the Esk in Musselburgh behind.  Great Willowherb is a tall hairy plant with pink and cream flowers and common, often thriving in damp places like the river here but is not as widespread as Rosebay Willowherb.