Sweet Rocket or Dame’s Violet is not really a native plant, but was introduced to Britain, probably by the Romans. It is originally from Turkey and Greece. It is a tall bushy biennial or short lived perennial, flowering the following spring/summer after sowing. The white/pink/purple flowers are 4 petalled(related to cabbage) and can be massed on stems 1m tall. They are highly scented and useful for cut flowers. Bees, butterflies, moths and hoverflies love them. It prefers reasonably fertile and moist soil, not acid, and in the right conditions will naturalise. A wonderful cottage garden plant. Sow in late spring, in prepared soil.
Seed from Shropshire
Pic courtesy of Algirdas at the Lithuanian language Wikipedia, CC BY-SA 3.0