Scientific name: Bidens cernua L.
Common name: Bur-marigold
Description
Habit: Annual, 35 to 70 cm high.
Stems: Hairless, erect.
Leaves: Opposite, linear-lanceolate, stalkless, coarsely toothed, unlobed.
Flowers: Greenish-yellow, flower-heads drooping, 25-40mm across; involucral bracts numerous, in 2 or 3 rows, the outer ones long and leafy; florets greenish-yellow, without styles; usually all tubular, but sometimes a few outer radiating florets present; receptacles with scales between florets.
Fruits: An achene, pappus of 2-4 rigid, tough bristles.
Habitat: Marshes and pond margins.
Distribution: Rare, mainly found on the limestone.
Native status: Native
Of conservation interest: No