Bidens trichosperma (coronata)
Crowned beggarticks
 
Bidens trichosperma, crowned beggarticks, is a tall, moisture-loving annual that brings a burst of bright yellow to wetlands and pond edges in late summer. Plants typically reach 1-4 feet tall, with branching stems and cheerful daisy-like flowers that bloom from August into October.
 
It thrives in full sun and wet to consistently moist soils, often appearing along marsh edges, floodplains, and shallow water where seasonal disturbance keeps competition low. In New England it commonly grows alongside species such as Bidens cernua, Eupatorium perfoliatum, Chelone glabra, Schoenoplectus tabernaemontani, and Carex lurida, forming part of diverse wetland plant communities.
 
Ecologically, crowned beggarticks is a valuable late-season nectar source. The flowers attract numerous pollinators including Bombus impatiens, Halictidae sweat bees, syrphid flies, and butterflies taking advantage of late-season forage. Its seeds are also eaten by wetland birds such as dabbling ducks and American goldfinch. The barbed seeds readily attach to fur or clothing—hence the name “beggarticks”—an effective dispersal strategy that helps the plant colonize newly exposed wet soils. In the right setting, it’s a lively and ecologically productive species that keeps wetland edges buzzing well into fall.
 
photo by Choess