Water hyacinth
Pontederia crassipes · Aquatic plants
A stand of it · Photo: Naturalist Tours / CC0
Also called Eichhornia crassipes
State noxious weed listing
- Idaho: Early detection
How to identify Water hyacinth
- Glossy round leaves on swollen spongy leaf stalks
- Showy lavender flower spikes with a yellow spot on the upper petal
- Long dark purple feathery roots
- Plants linked by runners into rafts
Similar plants
Water lettuce has velvety ridged leaves without swollen stalks, and frogbit has small round leaves without inflated stalks.
Growth profile
| Growing season | Grows rapidly in warm summer water and dies when water freezes, though some plants survive mild winters. |
|---|---|
| Starts growing | About 55 F water; fastest from 70 to 85 F |
| Light | Needs full sun |
| Depth | Surface of water of any depth |
| How it spreads | Runners producing daughter plants, and seeds |
| Habitat | Warm, still, nutrient rich water; sold for water gardens. |
Why it matters in a lake
One of the fastest growing plants known, able to double in a couple of weeks and cover water in thick rafts. It is on the Idaho early detection list.
Where it is found
- Idaho: Not yet found
- Oregon: Not recorded
- Wyoming: Not recorded
Classification
| Kingdom | Plantae |
|---|---|
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Commelinales |
| Family | Pontederiaceae |
| Scientific name | Pontederia crassipes |
Common duckweed
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Star duckweed
Purple fringed riccia
Turion duckweed
Mexican mosquito fern
Least duckweed
Floating crystalwortNeed a hand?
Is it taking over your lake?
We identify what is growing, map how much of it there is and build a control plan that targets it without harming the rest of the lake.
Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596