Stuckenia filiformis
Fineleaf Pondweed

Family:Pondweed (Potamogetonaceae)
AKA: Slender Pondweed, Threadleaf Pondweed
Photo taken on: August 10, 2021
Location: Almont Resort, GV, CO
Life Zones: Plains to foothills
Habitat: Cold slow- to fast moving water

Grows under water with branched stems to more than 3 feet long. Leaves are narrow to about 6" long with a blunt tip. Small flowers on a spike at the end of the stem bloom in late summer. It can survive winter under ice.

Flora of North America reference.