Weed Information: Erigeron bonariensis (fleabane, hairy)
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Erigeron bonariensis (fleabane, hairy)

Family: Asteraceae

Description

The flower heads about 1 cm broad with numerous white ray flowers. The bracts beneath the head very hairy. Although often found with Erigeron canadensis (horseweed), the two features above will readily distinguish between these species.

Characteristics

Flower Color
  • Yellow
  • Blue-purple
  • White
  • Multi-colored
Inflorescence Type (How the flowers are arranged on the plant)
  • Head
  • Panicle
Number of Petals
  • 0 (no petals)
  • 5 petals
  • more than 10 petals
Petal Separation
  • Completely free to base
  • United > 75% of length
Petal Tip
  • Pointed
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
Flower Width (Head width in the Asteraceae)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
Number of Sepals
  • sepals lacking
  • more than 10 sepals
Sepal Separation
  • Completely free to base
Sepal Tip
  • Pointed
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 1 style
Number of Stamens
  • 5 stamens
Stamens Attached to the Petals
  • Stamens attached to the petals
Stamens Connate (united)
  • Anthers united, syngynoecious

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 1 carpel
Ovary Position
  • Inferior (epigynous)
Fruit Type
  • Achene
Fruit Length at Maturity
  • 1 mm (.04 inch) or less
  • 2 mm (.08 inch)
Fruit Width at Maturity
  • 1 mm (.04 inch) or less
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
Leaf Type
  • Simple (including lobed leaves)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole absent (leaf sessile)
  • Petiole < 25% total length
Leaf Length (blade PLUS petiole)
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.60 inches)
  • 4 - 10 cm (1.60 - 4.0 inches)
Leaf Width
  • 1 - 5 mm (.04 - .20 inch)
  • 5 - 10 mm (.20 - .40 inch)
  • 1 - 2 cm (.40 - .80 inch)
Leaf Shape (simple leaves only)
  • Linear or filiform
  • Oblanceolate
  • Pinnately lobed
Leaf or Leaflet Margin
  • Dentate
  • Entire
  • Lobed
Leaf or Leaflet Blade Base
  • Acuminate (attenuate)
Leaf or Leaflet Tip
  • Acute
Leaf or Leaflet Blade Surface
  • Hirsute
  • Strigose
Succulence
  • Not succulent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
  • Aromatic
Life Cycle
  • Annual
Growth Habit (while flowering)
  • Erect, columnar (narrow)
Plant Height at Maturity
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
  • 4 - 6 dm (1.3 - 2.0 feet)
  • 6 - 8 dm (2.0 - 2.6 feet)
  • 8 - 10 dm (2.6 - 3.3 feet)
Wind Dissemination
  • Fruit, seed, or spore wind borne
Moisture Regime
  • Mesic
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • Tap Root

US State
  • Alabama
  • Arkansas
  • Florida
  • Georgia
  • Louisiana
  • Mississippi
  • North Carolina
  • South Carolina
  • Texas
  • Virginia
  • Hawaii
  • Arizona
  • California
  • New Mexico
  • Nevada
  • Oregon
  • Utah
  • Washington
Canadian Province or Territory
  • British Columbia

  • California Growers Weed Identification Handbook, 1968 - 1998 University of California Publication # 4030-1, See page: 77
  • Garden Weeds of Southern California, 1981, See page: 109
  • How to Know the Weeds, 1972, (ISBN# 0-697-04880-2) See page: 186
  • Weeds of California, 1970, State of California Publications and Documents. See page: 462, 463
  • Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 284
  • Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 68
  • Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 120
  • Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 122
  • 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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