Leaves with midribs evident when examined against light; flowers inconspicuous, not yellow.
Don E. Eyles, A Guide and Key to the Aquatic Plants of the Southeastern United States (Wahington D.C.:U.S. Government Printing Office, 1944) 31
2400×1638, 197.5 KiB
1024×698, 22.8 KiB
640×436, 11.7 KiB
320×218, 5.1 KiB