Western water hemlock
Cicuta douglasii · Aquatic plants
Whole plant · Photo: Garth Harwood / CC BY
Also called Douglas water hemlock, Cowbane, Water hemlock
State noxious weed listing
- Wyoming: County declared weed
How to identify Western water hemlock
- Leaflets toothed with veins running to the notches
- Umbrella shaped clusters of white flowers
- Chambered, swollen root base with yellow oily liquid
- Stout stems 2 to 6 feet
Similar plants
Water parsnip has once divided leaves with veins to the tooth tips; poison hemlock has purple spotted stems on dry ground.
Growth profile
| Growing season | Grows from early spring, flowers June to August and overwinters as the root crown. |
|---|---|
| Starts growing | About 45 F soil |
| Light | Full sun to part shade |
| Depth | Moist shoreline to about 6 inches of water |
| How it spreads | Seeds and root crowns |
| Habitat | Marshes, ditches, canal banks, pond edges and streambanks. |
Why it matters in a lake
One of the most poisonous plants in North America; a small bite of root can kill people and livestock. Wear gloves when handling.
Where it is found
- Idaho: Common
- Oregon: Common
- Wyoming: Occasional
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Apiales |
| Family | Apiaceae |
| Scientific name | Cicuta douglasii |
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