Rosebay willowherb, Chamerion angustifolium.
This species is abundant in wet slightly acidic open fields but it has earned the nicknames ‘fireweed’ and ‘bombweed’ as a result of its tendancy to colonize quickly on burnt ground and bomb sites during World War II. The plant’s rise from a local rarity is closely linked to the expansion of the railway network making it a perfectly natural inhabitant of Parkland Walk. WT
