Dame’s Rocket in the open woods at the Volga
Recreational Area in northeast Iowa. USA
Dame’s Rocket (Hesperis matronalis)
DESCRIPTION: Dame’s rocket is a showy, short-lived perennial with large, loose clusters of fragrant white, pink or purple flowers that bloom from May to August on flowering stalks 2-3 feet in height. This member of the mustard family has flowers with four petals. Many seeds are produced in long, narrow fruits. The leaves are oblong, sharply toothed, and alternately arranged. Leaves decrease in size as they ascend the stem. The overwintering rosette is easily identified from fall through spring. This species is often confused with garden phlox (Phlox paniculata)l. Unlike dame’s rocket, the phlox species have opposite leaves that are not toothed, and flowers with five petals, not four.
DISTRIBUTION AND HABITAT: Dame’s rocket is native to Eurasia but was introduced to North America in the 1600’s. This plant usually grows in moist and mesic woodlands, on woodland edges, along roadsides, and also in open areas.
LIFE HISTORY AND EFFECTS OF INVASION: Dame’s rocket is planted as an ornamental, but quickly escapes cultivation because of its prolific seed set. Unfortunately, part of its success can be attributed to its wide distribution in “wildflower” seed mixes. It generally produces a basal rosette the first year, flowering the following year. The plants are prolific bloomers and produce large quantities of seed from May into July. Each plant may have several clusters of flowers at various stages of development, enabling the plant to produce both flowers and seeds at the same time. The effects of dame’s rocket invasion are not known, but it may compete with native species.