Weed Information: Lupinus argenteus (lupine, silver)
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Lupinus argenteus (lupine, silver)

Family: Fabaceae

Description

There are many species of lupines and differentiating between them is usually left to the specialist. Most are native perennials with palmately compound leaves and terminal racemes. Lupines are commonly included in weed references due to their toxicity to livestock and the fact that they increase with overgrazing.

Characteristics

Flower Color
  • Red (or pink)
  • Blue
  • Blue-purple
  • Purple
  • White
  • Multi-colored
Inflorescence Type (How the flowers are arranged on the plant)
  • Terminal raceme
Number of Petals
  • 5 petals
Petal Separation
  • Completely free to base
  • United > 75% of length
Petal Tip
  • Bilobed
  • Rounded
Flower Symmetry
  • Flowers strongly irregular
Flower Length (Head length in the Asteraceae)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
  • 1.5 cm (.6 inch)
Flower Width (Head width in the Asteraceae)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
Number of Sepals
  • 5 sepals
Sepal Separation
  • United from 25% - 75% length
  • United > 75% of length
Sepal Tip
  • Pointed
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
  • 1.5 cm (.60 inch)
  • 2.0 cm (.80 inch)
  • 2.5 cm (1.0 inch)
  • 3.0 cm (1.2 inches)
Fruit Width at Maturity
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
Leaf Type
  • Compound palmate 4 or 5 leaflets
  • Compound palmate > 5 leaflets
Stipules
  • Foliaceous 2-4 mm (.08 - .16 in) long
  • Foliaceous 4-10 mm (.16 - .40 in) long
Tendrils
  • Tendrils absent
Venation
  • Palmate
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole 25% - 75% total length
  • Petiole > 75% total length
Leaf Length (blade PLUS petiole)
  • 4 - 10 cm (1.60 - 4.0 inches)
  • 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)
  • 1 - 2 dm (4.0 - 8.0 inches)
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Rounded
Leaf or Leaflet Tip
  • Acuminate (attenuate)
  • Acute
  • Rounded (obtuse)
Leaf or Leaflet Blade Surface
  • Sericeous or villous (silky)
  • Tomentose
  • Villous or sericious (silky)
Succulence
  • Not succulent

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Perennial
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)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Mesic
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • Tap Root

US State
  • Kansas
  • Arizona
  • California
  • Colorado
  • Idaho
  • Montana
  • North Dakota
  • New Mexico
  • Nevada
  • Oklahoma
  • Oregon
  • South Dakota
  • Utah
  • Washington
  • Wyoming
  • Nebraska
Canadian Province or Territory
  • British Columbia
  • Alberta
  • Saskatchewan

  • Common Weeds of the Canadian Prairies, 1963 (Cat# A53-1136-1) See page: 46
  • South Dakota Weeds, 1967 South Dakota State University, See page: 106
  • South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 96
  • Weeds of California, 1970, State of California Publications and Documents. See page: 261
  • Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 307
  • Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 335
  • Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 333
  • 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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