Spanish Needles

Bidens bipinnata L.

Asteraceae (Aster Family)

▲ seedling

▲ ▼ young plants

▲ ▼ flowering plants

▲ leaf

▲ inflorescence

▲ inflorescence, fruit and leaves

▲ mature fruit (right) and developing fruit (left)

▲ mature fruit, showing 3-spined needle-like fruit

Bidens bipinnata L., Spanish Needles: (Bayer Code: BIDBI; US Code BIBI)

Is a summer annual with opposite, finely divided (bipinnately compound) leaves
Flowers heads have 1-5 very short (0.25 inch) or absent yellow ray flowers, and 12-27 yellow disk flowers
Seeds mature to long, needle-like burs which attach to passing animals
Spanish needles is found in disturbed sites, open woods, pastures, right-of-ways, urban landscapes and non-crop areas, drier soils
Some similar species:
- Devil’s Beggarticks (Bidens frondosa) has pinnately-compound leaves with toothed, lanceolate leaflets, flowers lack ray flowers and the burs are short and attached to a triangular seed
- Nodding Beggarticks (Bidens cernua) has simple lanceolate leaves with toothed, lanceolate leaflets, 6-8 ray showy flowers (petals) per head and burs and seeds similar to devil’s beggarticks
- Tickseed Beggarticks (Bidens aristosa) has pinnately compound leaves with toothed, lanceolate leaflets (leaflets often more narrow than devils beggarticks) and 6-8 showy ray flowers (petals) per head and triangular, 2-burred seeds
- Swamp Beggarticks (Bidens tripartita) has simple lanceolate leaves with toothed margins, sometimes with 3 deep lobes; flowers lack ray flowers; it often grows in wet soils near ponds, lakes, rivers

(Updated January 19, 2019)