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

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

Root

Creeping rhizomes

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

Learn more about the author(s)

Heidi Kratsch

Also of Interest:

Nevada Noxious Weed Field Guide – Eurasian watermilfoil