Stem
- Aquatic weed up to 12 ft. long, submersed, branched near water surface, growing points often reddish; breaks into fragments easily
Leaves
- Whorled with 4 leaves per node; leaves are green to brown, less than 1.25 in. long and pinnately-divided with more than 14 pairs of narrow, opposite lobes, less than 0.4 in. long
Flower
- Pinkish and small, each with a small, bract-like leaf
- Occur in clusters on small, pencil-like stalks that emerge from water, 1-3 in. long; stem often bends to become parallel with the water surface after flowering
Other
- Most common in still or slow-moving water but can sometimes be found in fast-moving rivers, streams and irrigation ditches; known to occur in Carson City, Douglas and Washoe counties
- Perennial; reproduces by rhizomes, stem fragments and seed
Control
- Mechanical removal can be effective but must be done repeatedly; escaped stem fragments can form new plants; draining then allowing an empty water-body to freeze can be effective
- Aquatic herbicides such as 2,4-D, copper complexes, diquat, endothall, fluridone, and triclopyr are effective; large infestations should be treated a portion at a time to prevent low oxygen levels as plants decompose
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B.
2020,
Nevada Noxious Weed Field Guide – Eurasian watermilfoil,
Extension, University of Nevada, Reno, Field Guide
