"After the Luftwaffe had laid waste to much of east London during the blitz, the first living things to return to the bombsites were not people, but weeds. By the time the BBC announced Hitler’s suicide in May 1945, bracken was marching up the aisle of St James’s, Piccadilly, thornapple was blooming through Cheapside cellars and ragwort had scaled London Wall. Rosebay willowherb (previously an upland rarity) was now spreading so aggressively through the unhealed rubble that east Londoners had rechristened it bombweed."