Weed Information: Asclepias pumila (milkweed, low)
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Asclepias pumila (milkweed, low)

Family: Asclepiadaceae

Description

Very similar to whorled milkweed but much shorter, seldom over sixteen inches tall and the leaves alternate in a tight spiral (rather than whorled). This species and many other members of the genus are toxic to livestock.

Characteristics

Flower Color
  • Red (or pink)
  • Yellow
  • Yellow-green
  • Green
  • Purple
  • White
  • Multi-colored
Inflorescence Type (How the flowers are arranged on the plant)
  • Simple umbel
Number of Petals
  • 5 petals
Petal Separation
  • United at base only (<25% length)
  • United from 25% - 75% length
Petal Tip
  • Pointed
  • Rounded
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
Flower Width (Head width in the Asteraceae)
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
Number of Sepals
  • 5 sepals
Sepal Separation
  • Completely free to base
  • United at base < 25% length
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)
  • Filaments united, monodelphous

Carpel Separation
  • Carpels united (or one)
  • Carpels separated
Number of Carpels
  • 2 carpels
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Follicle
Fruit Length at Maturity
  • 4.0 cm (1.6 inches)
  • 4.5 cm (1.8 inches)
  • 5.0 cm (2.0 inches)
  • 6.0 cm (2.4 inches)
  • 7.0 cm (2.8 inches)
  • 8.0 cm (3.2 inches)
Fruit Width at Maturity
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
  • Whorled 3 per node
  • Whorled 4 per node
  • Whorled 5 - 8 per node
  • Whorled > 8 per node
Leaf Type
  • Simple (including lobed leaves)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole absent (leaf sessile)
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)
Leaf Shape (simple leaves only)
  • Linear or filiform
Succulence
  • Succulent
  • Not succulent
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
Leaf or Leaflet Tip
  • Acute
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Puberulent

Milky Juice
  • Juice milky
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
  • 5 - 10 cm (2.0 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
Wind Dissemination
  • Fruit, seed, or spore wind borne
Moisture Regime
  • Mesic
  • Arid
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • Rhizomatous
  • Tap Root

US State
  • Kansas
  • Texas
  • Colorado
  • Iowa
  • Montana
  • North Dakota
  • New Mexico
  • Oklahoma
  • South Dakota
  • Wyoming
  • Nebraska

  • South Dakota Weeds, 1967 South Dakota State University, See page: 132
  • South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 152
  • Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 61
  • Listed as a `Weed` by the Biota of North America Program, 2008 X
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