Flower Color

• Blue-purple
• Purple
• Brown/Black

Inflorescence Type (How the flowers are arranged on the plant)

• Head
• Solitary, axillary
• Solitary, terminal

Number of Petals

• 4 petals

Petal Separation

• United > 75% of length

Petal Tip

• Rounded

Flower Symmetry

• Flowers regular

Flower Length (Head length in the Asteraceae)

• 1.0 cm (.40 inch)
• 1.5 cm (.6 inch)
• 5.0 cm (2.0 inches) or more

Flower Width (Head width in the Asteraceae)

• 2 mm (.08 inch)
• 3 mm (.12 inch)
• 4 mm (.16 inch)
• 3.5 cm (1.4 inches)
• 4.0 cm (1.6 inches)
• 4.5 cm (1.8 inches)
• 5.0 cm (2.0 inches)
• > 5.0 cm (> 2.0 inches)

Number of Sepals

• 4 sepals

Sepal Separation

• United > 75% of length

Sepal Tip

• Pointed
• Rounded

Flower Sex

• Bisexual (perfect)

Number of Styles

• 1 style

Number of Stamens

• 4 stamens

Stamens Attached to the Petals

• Stamens attached to the petals

Stamens Connate (united)

• Filaments or anthers NOT united

Carpel Separation

• Carpels united (or one)

Number of Carpels

• 1 carpel

Ovary Position

• Inferior (epigynous)

Fruit Type

• Achene

Fruit Length at Maturity

• 3 mm (.12 inch)
• 4 mm (.16 inch)
• 5 mm (.20 inch)
• 6 mm (.24 inch)
• 7 mm (.28 inch)

Fruit Width at Maturity

• 1 mm (.04 inch) or less
• 2 mm (.08 inch)

Burs

• Fruit or seed NOT bur-like
• Fruit or seed bur-like

Leaf Arrangement

• Opposite

Leaf Type

• Pinnately dissected
• 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 dm (4.0 - 8.0 inches)
• 2 - 4 dm (8.0 - 16.0 inches)
• 4 - 6 dm (1.3 - 2.0 feet)

Leaf Width

• 4 - 10 cm (1.6 - 4.0 inches)

Leaf Shape (simple leaves only)

• Pinnately lobed

Leaf or Leaflet Margin

• Lobed
• Parted
• Ciliate

Leaf or Leaflet Blade Base

• Clasping

Leaf or Leaflet Tip

• Acuminate (attenuate)
• Acute

Leaf or Leaflet Blade Surface

• Spiny or prickly

Succulence

• Not succulent

Milky Juice

• Juice NOT milky (watery)

Woodiness

• Herbaceous
• Semi-woody

Spines or Thorns

• Spines on leaves or stems
• Spines on flowers\fruits AND leaves\stems

Aromatic (vegetative structures)

• Not aromatic

Life Cycle

• Biennial
• Perennial

Growth Habit (while flowering)

• Erect, columnar (narrow)

Plant Height at Maturity

• 6 - 8 dm (2.0 - 2.6 feet)
• 8 - 10 dm (2.6 - 3.3 feet)
• 1 - 1.5 meters (3.3 - 5.0 feet)
• 1.5 - 2.0 meters (5.0 - 6.6 feet)
• 2 - 2.5 meters (6.6 - 8.3 feet)

Wind Dissemination

• Not wind disseminated

Moisture Regime

• Semi-aquatic
• Seasonally saturated
• Mesic

Chlorophyll

• Present

Stem Cross Section

• Hollow (flowering stem at maturity)
• Ridged
• Round

Flowering Stem Leaves

• Stem leaves greatly reduced
• Stem uniformly leafy

Main Stem Branches

• Main stem unbranched
• Main stem branched

Root or Vegetative Propagule

• Tap Root

US State

• Illinois
• Kansas
• Kentucky
• Massachusetts
• Michigan
• Missouri
• New Jersey
• New York
• Ohio
• Pennsylvania
• Virginia
• Wisconsin
• West Virginia
• Indiana
• Maryland
• Colorado
• Iowa
• Minnesota
• Oregon
• Nebraska

Canadian Province or Territory

• Ontario

• Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 417
• Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 202
• Weeds of the Northeast, 1997 Cornell University ISBN# 0-8014-8334-4 See page: 220
• Listed as a `Weed` by the Biota of North America Program, 2008 X
• Listed in the WSSA Composite List of Weeds X