Online Virtual Flora of Wisconsin

Alliaria petiolata (M.Bieb.) Cavara & Grande

Family: Brassicaceae

garlic mustard

[Alliaria alliaria (L.) Britton, more...]

Robert H. Read

Paul Drobot

University of Wisconsin - Madison (WIS-VP)

Open Interactive Map

Etymology: Alliaria: from Allium meaning "onion" or "garlic"
Plants: erect, biennial, 12"-40" tall forb, forming large, dense mats, first year plants an evergreen, basal rosette; stems mostly unbranched, hairless
Leaves: alternate, coarsely toothed, stalked, strong garlic smell when crushed; lower kidney shaped, upper triangular
Flowers: white, 4-parted, 1/3" wide, petals rounded at the top, narrowing towards the base; inflorescence a short, terminal cluster (raceme) of stalked flowers; blooms April-June
Fruits: long, thin, 4-angled pods, both horizontal and pointing upward
Habitat: partial shade, shade; moderate moisture to moist; woods, woods edges
Invasiveness: Restricted Invasive - Eradicate!
Conservation Status: Introduced - naturalized; ecologically invasive

Invading forests of all kinds including oak-pine, oak-hickory, maple-basswood, beech-maple, pine plantations, wooded dunes with hemlock-balsam fir-white cedar, and disturbed woods. Also in fields, along roadsides and railroads, vacant lots, gardens and yards, waste areas, fencerows, farmyards, campgrounds, talus slopes, lakeshores; rarely in wetlands or dry sandy areas. One of our most destructive and aggressive forest invaders, introduced from Eurasia. Apparently ignored by most collectors but abundant across all counties in the state, especially near urban areas. First collected in 1938 in Milwaukee and Patman & Iltis (1961) noted this species as “occasional”. It has sadly exploded across the landscape since then.

All parts of the plant have a garlic-like aroma and are edible and delicious. This is a biennial, the first-year rosettes with rounded leaves somewhat resembling a Viola but with more conspicuous venation and an obvious odor. The large, triangular or cordate leaf blades are unusual among our mustards.