Online Virtual Flora of Wisconsin

Hesperis matronalis L.

Family: Brassicaceae

dame's rocket

Merel R. Black

Hugh H. Iltis

University of Wisconsin - Madison (WIS-VP)

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Etymology: Hesperis: from "evening" for evening fragrance of the flower
Plants: erect, biennial/perennial, 2'-3' tall forb; stems often with upper branches
Leaves: upper leaves not clasping
Flowers: purple to white, 4-parted, 3/4" wide, fragrant; inflorescence a loose cluster (raceme) of stalked flowers; blooms May-Sept.
Fruits: long, thin pod narrowing between the large seeds; stout, widely-spreading stalks
Habitat: full to partial sun; disturbed sites, woods, roadsides
Invasiveness: Restricted Invasive - Eradicate!
Conservation Status: Introduced - naturalized; ecologically invasive

Roadsides, vacant lots, fields, railroad corridors, mesic woods, floodplain forests, streambanks, thickets, waste areas, ditches. An extremely showy species, with white and pink-flowered forms often intermingled with the typical purple ones. Like Alliaria petiolata, this is an aggressive invader of forests and can form huge stands that shade out other vegetation. Often misidentified as a native Phlox, but obviously differing in the alternate leaves and corollas with only four, not five, petals. Native to Europe and first collected in 1913. Found in almost every county, but largely ignored by collectors. Malcolmia maritima (L.) W. T. Aiton, Virginia stock, has been collected on the UW Madison campus and along a road but it’s doubtful that these came from wild plants. It resembles H. matronalis in its non-clasping leaves, elongate ovary, and hirsute pubescence but differs in its pubescent fruits. Despite its common name, M. maritima is native to the Balkan Peninsula.