Report an Invasive Species
wnyprism@buffalostate.edu
(716) 878.4708
X
CONTACT US
Great Lakes Center, SAMC 319
SUNY Buffalo State
1300 Elmwood Ave., Buffalo, NY 14222
wnyprism@buffalostate.edu
(716) 878.4708
SUBSCRIBE TO LISTSERV
FOLLOW US
CONTACT
Water lettuce (Pistia stratiotes) cover. Photo Credit: Dr. Bill Haller, University of Florida.
Water Lettuce
COMMON NAME:
Water LettuceSCIENTIFIC NAME:
Pistia stratiotesORIGIN:
Africa and South AmericaDESCRIPTION:
Water lettuce is an often free-floating aquatic plant that resembles an open head of lettuce. Feathery roots grow under the plants, which can connect a large number of these plants by stolons. Leaves are light green, thick, softly hairy (pubescent), and have parallel veins and scalloped edges. Water lettuce produces a green berry that turns brown at maturity. Flowers are inconspicuous.HABITAT:
The plant can adapt to life in ponds, lakes and quiet areas of rivers and streams, but doesn't tolerate salt water. While water lettuce is limited by cold winter temperatures, several populations of water lettuce have been observed in New York and Ontario, and they may be successfully reproducing.THREAT:
Water lettuce forms thick mats that block sunlight and slow or prevent the growth of native aquatic plants. As the plant dies and decomposes, it removes oxygen from the water, which can disrupt fish communities. Dense mats of water lettuce can hinder swimmers and boaters, prevent other recreational uses of waterways, and restrict water flow in irrigation and flood control canals.MANAGEMENT:
Small and isolated infestations can be easily controlled manually (hand pulling). Larger infestations can be addressed using harvesters, large machines that scoop up plants. Once large infestations have been decreased in size and density using harvesters, hand removal can be used to finish the job. Chemical control is also effective.
WNY PRISM PRIORITY:
Early Detection Priority Species
Tier 2 - Eradication
ADDITIONAL RESOURCES:
NYS Prohibited and Regulated Species - Part 575:
PATHWAYS OF INVASION:
Water lettuce was introduced to North America as an aquarium and water garden plant. It is often spread by the release of aquarium plants.
REGIONAL DISTRIBUTION:
Water lettuce was first reported in the WNY PRISM region in 2011.
MAP (via iMapInvasives):
To view more information for each point, zoom in, click on the point and select the "Maximize" symbol. Click "More info" to open the iMapInvasives record.
This map shows confirmed observations (green points) submitted to the NYS Invasive Species Database.
Absence of data does not necessarily mean absence of the species at that site, but that it has not been reported there.
For more information, please visit iMapInvasives.