Watercress
Nasturtium officinale · Aquatic plants
Flowers or seeds · Photo: Tony KM / CC BY
Also called Water cress, Rorippa nasturtium aquaticum
How to identify Watercress
- Leaves divided into 3 to 9 round leaflets
- Small white flowers with 4 petals
- Hollow stems that float and root in water
- Peppery taste
Similar plants
Cutleaf water parsnip has toothed leaflets and umbrella flowers; American speedwell has undivided leaves.
Growth profile
| Growing season | Grows nearly year round in spring water, flowers April to September. |
|---|---|
| Starts growing | About 45 F water |
| Light | Full sun to part shade |
| Depth | Saturated soil to about 1 foot of water |
| How it spreads | Stem fragments and seeds |
| Habitat | Springs, cold streams, ditches and spring fed ponds. |
Why it matters in a lake
Fragments root easily and form floating mats. Wild plants can carry liver fluke and bacteria from livestock water.
Where it is found
- Idaho: Occasional
- Oregon: Occasional
- Wyoming: Occasional
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Brassicales |
| Family | Brassicaceae |
| Scientific name | Nasturtium officinale |
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Baltic rushNeed a hand?
Is it taking over your lake?
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