The Frog Blog – Aquatic Weed Wednesday

Happy Wednesday! Today we will look into a native aquatic plant common throughout the state of Ohio: American or Long-leaf pondweed (Potamogeton nodosus).

American Illinois Pond Weed

American pondweed is an interesting member of the diverse Potamogeton genus of aquatic plants. Although there is a wide variety of species in this genus, American pondweed has leaves that float up to the top of the water surface and expose themselves similarly to lilies. These leaves (sometimes referred to as “sun leaves”) will always have a well defined midvein going down the very center. Some other pondweed species also have these sun leaves but American pondweed have long submersed leaves as well giving credit to the “Long-leaf” name. The flowers and fruits of this species are very small and created via a large spike that pokes out of the water (see photo).

Although native, American pondweed can occasionally grow to nuisance levels. It can commonly reproduce via rhizome structures that are found within bottom sediments. These allow the plant to overwinter and allow the plant to sprout again if its upper portion is plucked from the sediment. So, if you want to pull this plant from your pond be sure to ensure the rhizome is also being pulled for best results. Many prefer to leave some American pondweed in their waterbodies though, as it the reproductive spike can provide food to waterfowl and the plant itself is excellent cover to aquatic organisms.

By: Edward Kwietniewski

Aquatic Biologist

AQUA DOC Lake and Pond Management

Edward Kwietniewski graduated from The State University of New York College of Environmental Science and Forestry (SUNY ESF) with a Bachelor’s degree in Aquatics and Fisheries Science. He also has a Master’s degree in Lake Management from the State University of New York College at Oneonta (SUNY Oneonta). He has a love for all things aquatic and is an avid fisherman.


Resources and External Links

Borman, Susan. Through The Looking Glass: a Field Guide to Aquatic Plants. Stevens Point, Wis. :Wisconsin Lakes Partnership, 1997. Print.