Tall pink wildflower – up to 1.5m high - that characterised London’s post-war bomb sites of the 1940s and ‘50s, and since spread along railways and canalsides. Grows on disturbed ground and beneficial for many pollinating insects. Each plant can produce up to 80,000 seeds carried in the wind by feathery parachutes, and the heat from fires and bonfires can help to germinate them, hence another name of 'fireweed'.

Find rosebay willowherb on a London Nature Trail at:

• Welsh Harp (Brent) Reservoir on the walk from Burnt Oak to Wembley

• Regent’s canal and Camley Street Natural Park on the walk from Swiss Cottage to King’s Cross

• Royal Docks, Bow Creek Ecology Park, River Lea and Wanstead Flats on the walk from Wanstead to Royal Docks