Skip

Invasive Species Sheet - Dame's Rocket

Invasive Species Identification Sheet

Dame's Rocket (Hesperis matronalis L.)

Alternate Common Names: Sweet-rocket, Damask-violet, Dame’s Violet, Mother-of-the-evening,
Dame’s-, Queen’s-, Rogues-, or Winter-gilliflower; Night-scented Gilliflower, Summer Lilac
- erect biennial or perennial herbaceous plant, 2'-3' tall; may be branched
- flowers purple (sometimes pink or white), mustard type (4 evenly-spaced petals); 3/4"-1" long
- leaves alternate with small teeth and long-pointed tips
- fruit less than 1/8" wide and, when mature, 2"-4" long; constricted between seeds when ripe

In flower, Dame’s Rocket is showy and fragrant (especially in the evening). The lower flowers open first, so that the tall stem may be thickly flowered at the tip while the lower part of the stem has ripening fruits growing upward and outward. Dame’s Rocket may be distinguished from Phlox by its flowers with 4 (not 5) petals and its alternate, finely-toothed (not opposite, untoothed) leaves. Dame’s Rocket leaves have branched hairs on the underside and unbranched hairs on the top surface (use hand lens). The upper stem leaves are smaller than the lower and may lack leaf stalks. Dame’s Rocket flowers early in its second summer. At maturity, the nearly stemless fruits split open from the bottom all the way to the top, leaving a thin membrane in the middle.

Dame’s Rocket is a garden escape also currently thought to be spread through “wildflower” seed mixes. Although it often does not cover large areas, it spreads rapidly from seed and can be very dense excluding native wildflowers in moist areas of meadows, forest edges, and bottom-land woods. Widely distributed in New England, it is perhaps most abundant or dense on soils high in calcium.