Garlic Mustard
Alliaria petiolataBrassicaceae
Whole Plant
Flower
Fruit
Leaf
Whole PlantFlowerFruitLeaf
Habitat
Habitat
Photos (c) Cheryl Comeau Beaton unless otherwise noted

Synonyms:

  • Alliaria officinalis, Erysimum alliaria, Sisymbrium alliaria

The Plant:

  • A highly fragrant, herbaceous biennial. In the first year, growth is low (3-7 inches) as a non-flowering basal rosette. In the second year flowering stems reach 3.3 feet tall.

The Leaves:

  • toothed
  • basal leaves kidney-shaped
  • long petioles
  • deeply veined-highly textured
  • basal rosette remains green throughout winter
  • stem leaves deltoid
  • alternate along stems
  • basal leaves 2.4-4 inches long and wide
  • stem leaves 1.2-3.1 inches long and wide, decrease in size up the stem

The Stem:

  • lacking the first year
  • green, smooth, upright

The Flowers:

  • Small, cruciform white flowers (.25 inches wide) with four petals. Blooms from April to May.

The Fruits:

  • pods or siliques (1-2.4 inches long and 0.8 inch wide)
  • green drying to a brittle brown
  • contain 10-20 shiny, black, cylindrical seeds
  • May
  • by June the plant dies back and the fruits persist

The Habitat:

  • shade tolerant
  • forest understories
  • moist, shady areas
  • roadsides, trails, forest edges

Dispersal:

  • seeds stick to clothing, shoes, and wildlife, and are also passively dispersed close to the parent plant
  • yard waste

Key ID Features:

  • fragrant
  • first year as basal rosette
  • heart shaped leaves
  • highly textured-deeply veined
  • 4 white petals
  • white taproot

Similar Species:

  • Field mustards

Notes:

  • Garlic mustard can rapidly overtake an area by emerging in early spring before other vegetation and through prolific seed production. Roots contain phytotoxins which may inhibit the growth of other plants.

Growth Form: Herb

Origin: Europe

Level of Invasiveness for Nantucket: Invasive

Level of Invasiveness for Massachusetts: Invasive

Massachusetts Cultivation Restrictions: importation ban, propagation ban




Credits: The Electronic Field Guide to the Invasive Plants of Nantucket (c) 2005-2006 Maria Mitchell Association, EFG Project, UMass Boston