Creeping Water Primrose
Latin name
Ludwigia peploides
Other names
Floating Primrose-willow, and wrongly as L. grandiflora
Family
Onagraceae
Flowering season
July to September
English distribution
It is thinly scattered in a few sites; mainly in the South
See the BSBI distribution map for Creeping Water
Habitat
It is a neophyte which grows in slow flowing water, where
it crowds out native plants and clogs waterways.
It was ntroduced from South America as an ornamental,
water garden plant. It is classed as an Invasive Alien.
Description
Creeping Water Primrose is a perennial herb with a
creeping stem that can reach 2m.
Flowers overtop the leaves and are up to 5cm across.
There are 5 bright yellow petals and 5 thin, pointed sepals.
Stamens are large and yellow, and the stigma is spherical
and yellow.
Aerial leaves are green and lanceolate - rather like
willowherb.
The fruit is a hard, cylindrical capsule
Although it can spread by seed, it mainly regenerates
from stem or root fragments. This makes it difficult to
remove mechanically, so complete eradication usually
depends on spraying with herbicides.
Although Creeping Water Primrose is an attractive plant,
it is classed as an alien, invasive and noxious weed.
It is listed under Schedule 9 to the Wildlife and Countryside
Act 1981 with respect to England and Wales and it is an
offence to plant or otherwise allow it to grow in the wild
(www.nonnativespecies.org/legislation).
It is one of the plants of interest to the NSSS (GB
Non-native Species Secretariat) who provide
further details on control, management and a Wanted
Poster for Creeping Water Primrose.
The colony shown in the pictures on this site were taken
in West Bay, Dorset. Efforts to erradicate these plants
were made in 2010, but were unsuccessful. Further
attempts were made in spring, 2011, and appeared to
have been successful. However, it re-appeared in
September 2014. It appears to be eradicated now (2022).
Previous page: Cotton Thistle
Next page: Dittander
Clogged waterway, West Bay, Dorset
Dense mat
Flower and leaves
Emerging flower - stamens
Fully open flower - stamens and stigma
Close-up of stigma and stamens
Sepals
Fruiting capsule
Leaves from above