Showy or Larger Bur Marigold
Bidens laevis
From Nearctica
Identification: Flowers golden yellow with conspicuous ray florets. Ray florets longer than wide, usually at least one inch long. Seeds (achenes) straight with apical barbs and without a central vertical ridge. Stem commonly tinged with red-purple. Leaves elongate, undivided, and only weekly dentate. Plant 1 to 3 feet in height.
Distribution: Most of eastern North America from New England south to Florida. Also an inhabitant of the southwestern United States.
Habitat: Bur Marigold is found in swamps, wet woods, and along the shores of lakes and ponds.
Flowering period: July to October.
Similar Species: Bur Marigold can be very difficult to distinguish from Nodding Bur Marigold. The ray florets of Nodding Bur Marigold are shorter than those of Bur Marigold and in some plants may be absent entirely. The seeds (achenes) of Nodding Bur Marigold are commonly curved and have a central, vertical ridge.