Althaea officinalis: 6′ high x 2′ wide / full sun to half shade / zone 3
The roots of this plant were traditionally used to make the confection marshmallows. All parts of the plant are edible, though; the roots and leaves, raw or cooked, and the flowers raw in salads. The roots can be harvested from around the edge of the plant without killing it; they’re rich in starch and very pleasant-tasting. The plant doesn’t mind wet feet, so it’s a good one for a wet area of the garden.