Bidens bipinnata Spanish needles Asteraceae BIBI; Bx, pb (DeCandido 2001); NY, hb; Q, j (Stalter and Lamont. 2002); K (DeCandido 2001); R, c

   

Bidens bipinnata.commons.wikipedia.org

Bidens bipinnata.commons.wikipedia.org. (Accessed 5/2014).

Bidens bipinnata is an annual herb, 30-170 cm tall, stem square. 

Leaves opposite, stalk 2-5 cm, blade about 2-15 cm long, 2-3 times pinnately divided, ultimate segments usually rounded. 

Flowers yellow, to 0.6 cm wide, longer than wide, rays few, usually shorter than disk, outer bracts at base of flower head 7-10, shorter than the inner, membranous bracts, flower stalks stiff, elongate. 

Bidens bipinnata, leaf, flower and fruit. © Kay Yatskievych, 2003. discoverlife.org

Bidens bipinnata, leaf, flower and fruit. © Kay Yatskievych, 2003. discoverlife.org (Accessed 11/2017).

Fruit dry, 1-seeded (achenes) linear 4-sided to 1-1.3 cm topped by 3-4 stout, pale tooth-like barbed bristles (awns) that attach to fur or clothing for dispersal, Aug.-Oct. 

Wetland status: UPL. 

Frequency in NYC: Infrequent but apparently widespread. 

Origin: Native. 

Habitat: Open, disturbed areas, edges.