Scientific Family
Asteraceae
Synonyms
Bidens odorata
Other common names
Spanish needle
shepherds needles
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Annual
Similar species
Bidens sp.
Height
To 3 feet
Riparian
Yes
Erect and much branched annual with 4-sided stems. Flowers mostly borne singly on long erect stems. A weed of many crops and orchards. Plants are erect when young, but bow under their own weight with age.
Annual plants with pinnately lobed leaves of 3 to 7 primary lobes; single flower heads or sometimes several; involucres (whorl of flower bracts) bell-shaped to top-shaped or hemispheric or broader, 1/4 to 1/2 inch diameter, disc florets 20 to 80+.
Habitat
Usually occurs in wetlands, but occasionally found in non-wetlands including roadsides and ditch banks.
Plant Community
Riparian
Disturbed Areas
Low elevation
3500
High elevation
6000
Flower Characteristics
5 to 8 white ray flowers and many yellow disc flowers, terminal flower heads number one to several.
Flower color
White, yellow
Flower shape
Daisy or dandelion-like
Tubular
No
First bloom month
May
Last bloom month
October
Flower clusters
None
Leaf and Stem Characteristics
Pinnate with 3 to 7 leaflets; leaflet margins are serrate.
Leaf type
Compound
Leaf color
Green
Leaf shape
Pinnatifid
Leaf margin
Toothed
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No
Fruit and Seed Characteristics
Fruits narrowly cylindric or slightly compressed, 4-angled, 1/2 inch long with awns at tip.
Fruit type
Achene
Fruit color
Reddish-brown