Family: Brassicaceae, Mustard view all from this family
Description The crushed leaves and stems of this invasive forest weed have a garlic-like odor when crushed.
Habit: introduced annual or biennial herb; single thin stem, usually unbranched, rises from a basal rosette; mat-forming.
Height: 0.5-4.25 ft (0.15-1.3 m)
Leaf: in basal rosete, heart- or kidney-shaped, long-stalked, 0.6-3.5 in (15-88 mm) wide, length less than width; on stem, alternate, more triangular, shorter-stalked, toothed, to 6 in (150 mm) long and wide.
Flower: small, white, 0.3 in (8 mm) wide, with four petals forming the shape of a cross; held in flat round terminal cluster.
Fruit: long slender pods, rectangular in cross-section, 1-3 in (3-8 cm) long, to 0.1 in (2.5 mm) thick; held erect or horizontal on short stalks.
Flower April to June.
Habitat Wide range of moist to dry sites: roadsides, trails, railways, streambanks, waste places, fields, shaded woodlands, bluffs, thickets, steep slopes, disturbed fields, floodplains, woods, shaded forest floor; to 4000 ft (1200 m).
Range Native to Europe; introduced to North America by 1868; now naturalized throughout the continent, from Quebec and Ontario, south to Georgia and Tennessee, west to Oklahoma, northwest to Utah and Idaho; also in the Pacific Northwest from Oregon north to Alaska; not reported in Montana, Wyoming, or South
Discussion Considered weedy and invasive in most locations; listed as noxious and/or prohibited in 8 states. Garlic mustard is particularly problematic in woodlands; it invades areas disturbed by human activities and appears to be aided by white-tailed deer that prefer to eat native wildflowers and leave garlic mustard untouched.