Najas gracillima

Najas gracillima, the slender waternymph, is a submerged species of aquatic plant in the Hydrocharitaceae family. found in lakes and streams. It is native to China, Russian Far East, Japan, Korea, Taiwan, Iran, Alberta, Ontario, Newfoundland, Nova Scotia, New Brunswick, the eastern United States. It is also considered introduced and naturalized in France, Spain, Italy and California.
Najas gracillima is a small aquatic annual with branching stems. The unisexual flowers are produced in the axils of the branchlets and bases of the leaf sheaths. It is listed as endangered in Minnesota. It lives in soft-water lakes and ponds with mud and silt bottoms, and appears to be sensitive to water turbidity, warming, and eutrophication.