Bidens cernua, Nodding Bur-Marigold at Toadshade Wildflower Farm
Nickender Zweizahn, Bidens cernuus / Bidens cernua is a plant species in the sunflower family, widespread across much of Eurasia and North America.[6][7] It is commonly called nodding beggarticks[8] or nodding bur-marigold,
Bidens cernua (bur marigold, nodding beggartick)
Nodding Bur-Marigold, Bidens cernua | Jeremy Bartlett's LET IT GROW blog
Nodding Bur Marigold, PA Ecotype, Bidens cernua, PA Ecotype seed