Stem

Floating aquatic plant that grows at water surface; often highly branched

Leaves

1 submerged and 2 floating leaves whorled around stem at each node
Floating leaves are oval, flat, 1-2.5 in. wide and covered with short hairs less than 0.12 in. long that are shaped like an egg-beater
Submerged leaves are white to brown, fine, hair-like, up to 1 in. long and resemble roots

Flower

No true flowers; some submerged leaves develop spores, but they are not viable

Root

No true roots, but submerged leaves act as roots

Other

Grows best in areas that do not experience extended periods of freezing temperatures; not known to occur in Nevada
Perennial; reproduces by stem fragments; can form a mat over 1.5 ft. thick under favorable conditions
Listed on the Federal Noxious Weed List

Control

Mechanical removal can be effective but must be done repeatedly; escaped stem fragments can form new plants
Aquatic herbicides such as diquat and fluridone are effective

Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Giant salvinia, Extension, University of Nevada, Reno, Field Guide

Extension Associated Contacts

Heidi Kratsch

Also of Interest:


Needs Assessment for Noxious Weeds in Churchill County: Part 4 of 5 - Criteria for Herbicide Use and Selection This fact sheet is the fourth in a series of five that reports the results of a needs assessment survey completed by faculty in University of Nevada Cooperative Extension (UNCE). The survey attempted to identify the major issues related to the management and control of weeds in N... Davison, J., Powell, P., Schultz, B., and Singletary, L. 2012, University of Nevada Cooperative Extension
Nevada’s Priority Agricultural Weeds: Hoary Cress Plants commonly referred to as hoary cress (Cardaria sp.), or short whitetop, are one of three different but closely related perennial forbs. The Cardaria species are widespread across all eleven Western states, including every county in Nevada. B. Schultz, S. Foster 2021, Extension, University of Nevada, Reno, SP-21-03
Nevada Noxious Weed Field Guide – African mustard African mustard is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., H. Kratsch, Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Common crupina Common crupina is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Common St. Johnswort Common St. Johnswort is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide

Associated Programs

Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans

Grow Your Own, Nevada!

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Green Industry Training

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Nevada Noxious Weed Field Guide – Giant salvinia