Leaves opposite, simple, linear to lanceolate, pointed at the tip, more or less rounded at the sessile or slightly clasping base, with or without teeth, smooth or hairy, up to 6" long, up to 1½" wide. Stem erect or sometimes growing along the ground and rooting at the nodes, smooth or hairy, often branched, up to 5' tall. Flowers many, crowded together into a head, the outer yellow and flat, the inner yellow and tubular, forming a disk, with several heads per plant, each head subtended by 5-8 narrow, leafy bracts. Sepals absent. Petals yellow; some united to form flat rays up to 2/3" long and 1/3" wide, others yellow, 5-lobed, united below into a tube. Flower heads are erect, but then become nodding with age. Stamens 5 Ovary inferior. Fruit an achene, mostly flat, broadest at top, tapering to a narrow base, green-black, barbed along the edge, up to 1/3" long, about 1/10" broad, with four stiff barbed awns at the upper end.
Taxonomy and Systematics
Genus: Bidens L.
Species: Bidens cernua L.
Common Name: Nodding Beggar's Tick
Synonyms: Bidens cernua L. var. cernua nodding bur-marigold
Bidens cernua L. var. dentata (Nutt.) B. Boivin
Bidens cernua L. var. elliptica Wiegand
Bidens cernua L. var. integra Wiegand
Bidens cernua L. var. minima (Huds.) Pursh
Bidens cernua L. var. oligodonta Fernald & H. St. John
Bidens cernua L. var. radiata DC.
Bidens glaucescens Greene
Campus distribution and habitat
Flowers August-October around ponds and lakes, along streams, swamps, wet meadows, roadside ditches, marshes, bogs, and in areas of disturbed, wet soils.
Native to U.S.
Other common names include: Sticktight, Nodding Beggar's Ticks, Nodding Beggarsticks, Nodding Bur-Marigold
It is fairly easy to distinguish Nodding Bur-Marigold from other Bidens spp. because of its undivided leaves and achenes with 4 awns (rarely fewer)
- "Plants Profile for Bidens Cernua." PLANTS profile. National Resource Conservation Service, n.d. Web. 20 Oct. 2010. <http://plants.usda.gov/java/profile?symbol=BICE>.
- Rook, Earl J.S. "Nodding Bur Marigold." Rook.org. N.p., n.d. Web. 20 Oct. 2010. <http://www.rook.org/earl/bwca/nature/aquatics/bidenscer.html>.
- "Nodding Bur-Marigold." Illinois Wild Flowers. N.p., n.d. Web. 20 Oct. 2010. <http://www.illinoiswildflowers.info/wetland/plants/bur_marigold.htm>.