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Invasive Species Sheet - Garlic Mustard

Invasive Species Identification Sheet

Garlic Mustard (Alliaria petiolata (Bieb.) Cavara & Grande)

Alternate Latin names: Erysimum alliaria L.; Sisymbrium alliaria Scop.; Alliaria officinalis Andrz.; Alliaria alliaria of various authors; Alternate common names include Hedge-mustard
- biennial, herbaceous plant; grows 1'-3 1/2' tall
- flowers white; mustard-like with four 1/4" long evenly-spaced petals; blooms Spring/Summer
- leaves wide with heart-shaped leaf bases that never clasp around the flower stalk
- long-stemmed basal leaves are rounded or kidney-shaped with scalloped margins
- flowering stalk has alternate, increasingly triangular, leaves with large, pointed teeth
- young, crushed leaves and the slender, white taproot have unusual, rank, garlic odor
- seed pods 1"-2 1/2" long; slender relative to length; 4 angled,

Even without its white, mustard-type flowers and long, slender seed pods, Garlic Mustard is readily distinguished by its leaves that are wide, strongly-veined and (when young) garlic scented. There are typically 3 or 4 basal leaves each 2" (up to 7") wide that grow on long stems out of the top of the root. Leaves on the tall flowering stalk are short-stemmed and smaller than the basal leaves (but may be up to 2 1/2" wide). First-year plants have only a few long-stemmed, scallop-margined basal leaves (they do not send up a flowering stalk). After
setting seed the second year, the plant dies, but the flower stalks and seed pods may dry and remain standing.

Garlic Mustard fruits grow upward and outward on short, thickened stalks. Early fruits attached lower on the main stalk extend higher than the small flowers still blooming at the top of the stalk.

Garlic Mustard grows tall before other plants in early Spring. Once a few plants get established, Garlic Mustard multiplies into a dense stand that may easily shade out native wildflowers on trailsides, wetland borders, floodplains, and in open woods. Seeds remain viable 2-5 years.