Northern Prairie Wildlife Research Center
PONDWEED FAMILY (Potamogetonaceae)
IND. STATUS: OBL
FIELD CHARACTERISTICS: An aquatic, perennial herb. Fully developed submerged leaves have a characteristic quarter-moon shape because of their strongly-arched, folded condition. The submerged leaves are (2.5)3.5-7.2 cm. wide with 24-40(52) nerves. Floating leaves (if present) are elliptical, 4-10 cm. long with 28-50 nerves. Fruits are 4-5 mm. long, including the beak. In flower from July to September.
ECOLOGICAL NOTES: Large-leaved pondweed is found in lakes and rivers, usually at depths less than 9 feet, but it has been found in waters to 18 feet in depth.
SOURCE: Fernald (1970); and Voss (1972).