Nodding Bur-marigold - Bidens cernua


Short to tall plant with erect stems. Leaves opposite, linear lanceolate to lanceolate, toothed and unstalked. Flowerheads yellow, 15 to 25 mm, nodding, with or without rays. Outer flowers bracts 5 to 8, leaf like, the inner with dark streaks.

Similar Species

Bidens tripartita and Bidens frondosa; other Bidens are known to be naturalised in Britain and may turn up.  Identification is tricky and the key in Stace (4th edition) should be referred to; details of leaf and leaflet shape, and the shape of the achenes, is usually needed. 

Identification difficulty
ID guidance

Leaves tapered to base, but sessile; leaves not lobed, although serrated; achenes flattened with backward directed barbs. 

Recording advice

A photograph showing leaves as well as flowers; this species can't be verified from a photo just of he flowers


Moist habitats. Margins of ponds, lakes, rivers and canals.

When to see it

Flowering July to September.

Life History


UK Status

Scattered throughout much of Britain though scarce in the south west.

VC55 Status

Quite scarce in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 12 of the 617 tetrads.

In the current checklist (Jeeves 2011) it is listed as scarce. 

It is on the VC55 Rare Plant Register

be our species champion

Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map