Weed Information: Acer negundo (box-elder)
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Acer negundo (box-elder)

Family: Aceraceae

Description

New growth covered with a blueish-white film which is botanically referred to as `glaucous bloom.` Despite the common name and the pinnate leaves, this tree is really a maple as is evident from the fruit.

Characteristics

Flower Color
  • Yellow-green
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary cluster
  • Axillary racemes
Number of Petals
  • 0 (no petals)
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 1 mm (.04 inch)
  • 2 mm (.08 inch)
  • 3 mm (.12 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
  • United > 75% of length
Sepal Tip
  • Rounded
Flower Sex
  • Unisexual (monoecious or dioecious)
Number of Styles
  • Styles lacking (male flowers only)
  • 1 style
Number of Stamens
  • stamens lacking (female flowers only)
  • 5 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 0 (male flowers only or plants producing spores)
  • 2 carpels
Ovary Position
  • Halfway (perigynous)
  • Inferior (epigynous)
Fruit Type
  • Schizocarp
  • Samara
Fruit Length at Maturity
  • 2.5 cm (1.0 inch)
  • 3.0 cm (1.2 inches)
  • 3.5 cm (1.4 inches)
  • 4.0 cm (1.6 inches)
Burs
  • Fruit or seed NOT bur-like
Fruit Width at Maturity
  • more than 4.0 cm (> 1.8 inches)

Leaf Arrangement
  • Opposite
Leaf Type
  • Compound odd pinnate < 8 leaflets
  • Trifoliolate (3 leaflets)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole < 25% total length
  • Petiole 25% - 75% total length
Leaf Length (blade PLUS petiole)
  • 2 - 4 dm (8.0 - 16.0 inches)
Leaf Width
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
Leaf or Leaflet Margin
  • Dentate
  • Lobed
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Oblique
Leaf or Leaflet Tip
  • Acute
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Lower leaf surface more hairy
  • Pubescent
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
  • more than 5.0 meters (16.6 33 feet)
Wind Dissemination
  • Fruit, seed, or spore wind borne
Moisture Regime
  • Mesic
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • 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
  • Montana
  • North Dakota
  • New Mexico
  • Nevada
  • Oklahoma
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
  • Nebraska
Canadian Province or Territory
  • British Columbia
  • New Brunswick
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Alberta
  • Manitoba
  • Saskatchewan
  • Yukon
  • Northwest Territory
Other
  • District of Columbia

  • Ontario Weeds, 1992 Agdex 640, Publication #505 See page: 137
  • Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 31
  • Weeds of the Northeast, 1997 Cornell University ISBN# 0-8014-8334-4 See page: 354
  • Listed as a `Weed` by the Biota of North America Program, 2008 X
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