European frog-bit
(Hydrocharis morsus-ranae)
This species is Introduced in the United States
Appearance
Hydrocharis morsus-ranae is a free-floating aquatic plant that resembles a miniature water lily.
Foliage
The leaves of the plant are round, and heart-shaped, (the size of a Canadian two-dollar coin) with veins coming off the mid-vein that arch broadly following the shape of the leaf. The undersides of the leaves are dark purplish-red and have a spongy coating, which helps the plant float on top of the water.
Flowers
It has a single white flower approximately 0.6 in. (1.5 cm) in diameter with three rounded petals and a yellow center.
Fruit
Seeds are approximately 0.04 in. (1 mm) long.
Ecological Threat
In the fall, Hydrocharis morsus-ranae breaks apart and decomposes, falling to the bottom of the lake. The decomposition of huge volumes of vegetation in the water can deplete dissolved oxygen levels. If there are insufficient amounts of oxygen, fish and other aquatic organisms can die. These thick mats can also impede the movement of large fish and diving ducks.
Citations
Rawlins, K.A., R.L. Winston, C.T. Bargeron, D.J. Moorhead, and R. Carroll. 2018. New Invaders of the Northeast and Northcentral United States. USDA Forest Service, Forest Health Assessment and Applied Sciences Team, Morgantown, West Virginia. FHTET-2017-04. Retrieved from https://bugwoodcloud.org/resource/pdf/FHTET-2017-04_New%20Invaders_NE.pdf
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Lists - This map identifies those states that have this species on their invasive species list or law.
Invasive Listing Sources
- Alberta Fisheries Act
- Idaho Noxious Weeds
- Indiana Invasive Species Council - Invasive Plant List
- Indiana Pest Species
- Indiana Prohibited Plant Species
- Maryland Aquatic Nuisance Species Plan
- Michigan’s Invasive Species Watch List
- Michigan’s Prohibited and Restricted Species
- Mid-Atlantic Field Guide to Aquatic Invasive Species
- Minnesota DNR invasive species list
- National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
- New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture, Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
- New Hampshire Prohibited Aquatic Species
- New Invaders of the Northeast and Northcentral
- New Jersey Invasive Species Strike Team 2017 Invasive Species List
- New York Regulated and Prohibited Invasive Species - Prohibited
- Ontario’s Invading Species Awareness Program Tracked Species List
- Oregon Noxious Weeds
- Pennsylvania Department of Conservation and Natural Resources Invasive Plants
- Pennsylvania Noxious Weeds
- Pennsylvania's Field Guide to Aquatic Invasive Species
- To be proposed for MISC
- Vermont Noxious Weeds
- WeedUS - Database of Plants Invading Natural Areas in the United States
- Wisconsin Noxious Weeds
- Wisconsin's Invasive species rule – NR 40
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Superorder: Lilianae |
| Order: Alismatales |
| Family: Hydrocharitaceae |
| Genus: Hydrocharis |
| Hydrocharis morsus-ranae |
References
Common Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.
Scientific Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.