Iberis amara. Easy-to-grow annual that forms densely-headed, fragrant flowers in luminous white. Quick to bloom and has a low spreading habit that makes a nice ground cover for many months.
Leaves and flowers can be eaten raw and have been used as a bitter tonic and for alleviating indigestion.
Sow indoors 6-8 weeks before the last frost or direct sow after the last frost. Water regularly until established.