Giant salvinia
Salvinia molesta · Aquatic plants
A stand of it · Photo: Martin Rady / CC BY
Also called Salvinia, Kariba weed
State noxious weed listing
- Idaho: Early detection
How to identify Giant salvinia
- Oval floating leaves in pairs, about 1/2 to 1 1/2 inches
- Stiff hairs on leaf tops joined at the tips like tiny eggbeaters
- Leaves fold and stack into chains as mats thicken
- A third finely divided leaf hangs below like roots
Similar plants
Duckweeds are much smaller with smooth fronds, and common salvinia has hairs that are not joined at the tips.
Growth profile
| Growing season | Grows rapidly in warm water from spring through fall and is killed when ice forms on the plants. |
|---|---|
| Starts growing | About 50 F water; fastest from 68 to 86 F |
| Light | Full sun to partial shade |
| Depth | Surface of water of any depth |
| How it spreads | Breaking stems and buds; no viable spores |
| Habitat | Warm, still, nutrient rich water; sold for ponds and aquariums. |
Why it matters in a lake
Can double in about a week and form mats several inches thick. It is a federal noxious weed and 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 | Polypodiopsida |
| Order | Salviniales |
| Family | Salviniaceae |
| Scientific name | Salvinia molesta |
Common duckweed
Columbia watermeal
Mosquito fern
Giant duckweed
Star duckweed
Purple fringed riccia
Turion duckweed
Mexican mosquito fern
Least duckweed
Floating crystalwortNeed a hand?
Is it taking over your lake?
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