Weed Information: Youngia japonica (hawksbeard, Asiatic)
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Youngia japonica (hawksbeard, Asiatic)

Family: Asteraceae

Description

An annual with stem leaves few or lacking. The heads with one series of involucral bracts which become strongly reflexed at maturity. The basal leaves are pinnately lobed and hairy, the lobes progressively smaller toward the base.

Characteristics

Flower Color
  • Yellow
Inflorescence Type (How the flowers are arranged on the plant)
  • Cyme (simple or branched)
  • Head
  • Panicle
Number of Petals
  • 5 petals
  • more than 10 petals
Petal Separation
  • Completely free to base
  • United > 75% of length
Petal Tip
  • Square
  • Toothed
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
Flower Width (Head width in the Asteraceae)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
  • 1.5 cm (.60 inch)
Number of Sepals
  • sepals lacking
  • 5 sepals
  • 6 sepals
  • 7 sepals
  • 8 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)
  • 3 mm (.12 inch)
Fruit Width at Maturity
  • 1 mm (.04 inch) or less
  • 2 mm (.08 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • All basal
  • Alternate
Leaf Type
  • Simple (including lobed leaves)
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)
  • 4 - 10 cm (1.60 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
Leaf Width
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.6 inches)
  • 4 - 10 cm (1.6 - 4.0 inches)
Leaf Shape (simple leaves only)
  • Lyrate
  • Pinnately lobed
Leaf or Leaflet Margin
  • Lobed
Leaf or Leaflet Blade Base
  • Acute (cuneate)
  • Truncate
Leaf or Leaflet Tip
  • Acute
  • Rounded (obtuse)
Leaf or Leaflet Blade Surface
  • Hirsute
  • Puberulent
Succulence
  • Not succulent

Milky Juice
  • Juice milky
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not 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)
Wind Dissemination
  • Fruit, seed, or spore wind borne
Moisture Regime
  • Mesic
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • Tap Root

US State
  • Alabama
  • Arkansas
  • Florida
  • Georgia
  • Kentucky
  • Louisiana
  • Mississippi
  • North Carolina
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • Hawaii
  • Maryland
  • California
Other
  • Puerto Rico
  • Virgin Islands
  • District of Columbia

  • Weeds of Southern Turfgrasses, 1992 Univ. of Florida, Gainesville Publication # SP-79, See page: 113
  • 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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