Weed Information: Amorpha fruticosa (indigobush)
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Amorpha fruticosa (indigobush)

Family: Fabaceae

Description

A much branched shrub, commonly found along the margins of streams and lakes but also in other sites. Flowers with the peculiar odor of fake grape bubble gum. Fruit a 1-seeded legume. Planting by federal agencies has greatly expanded the range of this weedy species.

Characteristics

Flower Color
  • Purple
  • Red-purple
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary racemes
Number of Petals
  • 1 petal
Petal Separation
  • Completely free to base
Petal Tip
  • Rounded
Flower Symmetry
  • Flowers regular
  • Flowers strongly irregular
Flower Length (Head length in the Asteraceae)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
Flower Width (Head width in the Asteraceae)
  • 1 mm (.04 inch)
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Number of Sepals
  • 5 sepals
Sepal Separation
  • United from 25% - 75% length
Sepal Tip
  • Pointed
  • Rounded
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 1 style
Number of Stamens
  • 10 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments united, monodelphous

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 1 carpel
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Capsule, 1-celled
  • Legume
Fruit Length at Maturity
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
Fruit Width at Maturity
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
Leaf Type
  • Compound odd pinnate < 8 leaflets
  • Compound odd pinnate > 8 leaflets
Stipules
  • Foliaceous 2-4 mm (.08 - .16 in) long
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole < 25% total length
Leaf Length (blade PLUS petiole)
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
Leaf Width
  • 4 - 10 cm (1.6 - 4.0 inches)
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Rounded
Leaf or Leaflet Tip
  • Notched (emarginate, retuse)
  • Acute
  • Mucronate
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Glandular
  • Puberulent
  • Punctate
  • Sericeous or villous (silky)
  • Villous or sericious (silky)
Succulence
  • Not succulent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Woody
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Perennial
Growth Habit (while flowering)
  • Erect, spherical (bushy)
Plant Height at Maturity
  • 1.5 - 2.0 meters (5.0 - 6.6 feet)
  • 2 - 2.5 meters (6.6 - 8.3 feet)
  • 2.5 - 5 meters (8.3 - 16.6 feet)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Semi-aquatic
  • Seasonally saturated
  • Mesic
Chlorophyll
  • Present

Stem Cross Section
  • Round
Flowering Stem Leaves
  • Stem uniformly leafy
Main Stem Branches
  • Main stem branched

Root or Vegetative Propagule
  • Rhizomatous
  • Tap Root

US State
  • Alabama
  • Arkansas
  • Connecticut
  • Delaware
  • Florida
  • Georgia
  • Illinois
  • Kansas
  • Kentucky
  • Louisiana
  • Massachusetts
  • Maine
  • Michigan
  • Missouri
  • Mississippi
  • North Carolina
  • New Hampshire
  • New Jersey
  • New York
  • Ohio
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • Wisconsin
  • West Virginia
  • Indiana
  • Maryland
  • Rhode Island
  • Vermont
  • Arizona
  • California
  • Colorado
  • Iowa
  • Idaho
  • Minnesota
  • North Dakota
  • New Mexico
  • Oklahoma
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
  • Nebraska
Other
  • District of Columbia
Canadian Province or Territory
  • New Brunswick
  • Ontario
  • Quebec
  • Manitoba

  • Aquatic and Riparian Plants of the West, 2003 (ISBN# 1-879906-59-7) See page: 219
  • Nebraska Weeds, 1979 Nebraska Dept. of Ag., Lincoln NE, See page: 111
  • Listed as a `Weed` by the Biota of North America Program, 2008 X
  • Listed in the WSSA Composite List of Weeds X
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