Bidens beckii Torr. ex Spreng.
Family: Asteraceae
water beggar-ticks, water-marigold
Bidens beckii image
Linda W. Curtis  
Etymology: Megalodonta: Greek for "large-toothed," referring to pappus awns
Plants: erect, perennial, aquatic forb; from rhizomes
Leaves: opposite; submersed leaves finely cut, thread-like with smooth edges; emerged leaves stalkless, lance-like with toothed edges
Flowers: head 1"-1 1/2" wide with 1/3"-1/2" long, yellow rays, disk 1/3" wide; inflorescence of one head at the end of a sturdy stalk
Fruits: dry seed with 3-6 barbs
Habitat: clear water to 12'; in soft sediment soil
Conservation Status: Native