Floating primrose willow
Ludwigia peploides · Aquatic plants
A stand of it · Photo: Sam Kieschnick / CC BY
Also called Creeping water primrose, Water primrose, Ludwigia peploides ssp. montevidensis
State noxious weed listing
- Oregon: B list (T)
How to identify Floating primrose willow
- Yellow 5 petaled flowers about 1 inch across
- Shiny oval to oblong floating leaves on reddish creeping stems
- White spongy roots at the stem joints
- Stems mostly smooth
Similar plants
Uruguay water primrose has larger, often 6 petaled flowers and hairy upright stems, and water purslane has tiny flowers without petals.
Growth profile
| Growing season | Floating rosettes form in spring, growth peaks in warm summer water, flowers bloom from June to October, and stems die back in winter while rooted crowns and fragments survive. |
|---|---|
| Starts growing | About 50 to 55 F water; fastest above 70 F |
| Light | Needs full sun |
| Depth | Moist shoreline to about 6 feet |
| How it spreads | Stem fragments and seeds |
| Habitat | Shallow ponds, sloughs, ditches and lake margins over soft mud at low elevations. |
Why it matters in a lake
Forms thick mats over shallow water that lower oxygen and trap sediment. It is on the Oregon noxious weed list, and stem fragments spread it to new sites.
Where it is found
- Idaho: Not recorded
- Oregon: Occasional
- Wyoming: Not recorded
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Myrtales |
| Family | Onagraceae |
| Scientific name | Ludwigia peploides |
American pondweed
Floating leaf pondweed
Yellow pond lily
Fragrant water lily
Water smartweed
Floating marshpennywort
Uruguay water primrose
Watershield
Water purslane
Hairy watercloverNeed a hand?
Is it taking over your lake?
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