Seasonal Wild Flowers

Latin name

Bidens tripartita

Other names

Tripartite Bur-marigold

Family

Asteraceae

Flowering season

July to October

English distribution

It is found throughout the country except for parts of the

North.

For a map see the Botanical Society of Britain and Ireland

– Trifid Bur-Marigold

Habitat

It grows by ditches, ponds, streams and slow moving

rivers.

Description

Trifid Bur-Marigold is a native, annual, erect, herb growing

up to 75cm.

Flowerheads are solitary and up to 2.5cm across.

There are no ray florets, just yellow disk florets.

Florets are tubular and 4 angled. 

There are 5 stamens and 1 style which divided into 2

linear stigmatic arms.

The akinetes (seeds) are 4-sided, compressed and up

to 8mm.The angles are barbed and extended to form 

barbed bristles (best seen in the related species, 

Nodding Bur-marigold. The barbed bristles are used in

dispersal by attachment to animals, and replace the

feathery pappus seen in other members of the family.

The inner bracts (phyllaries)are broadly ovate and are

green and brown. There are up to 8 outer phyllaries which

are leaf-like.

Leaves are up to 15cm, ovate to lanceolate and coarsely

toothed.

The stems are much branched.