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Potamogeton nodosus (Longleaf pondweed)
Marcus, Joseph A.

Potamogeton nodosus

Potamogeton nodosus Poir.

Longleaf Pondweed, Knotty Pondweed

Potamogetonaceae (Pondweed Family)

Synonym(s): Potamogeton americanus, Potamogeton fluitans

USDA Symbol: PONO2

USDA Native Status: L48 (N), HI (N), PR (N), CAN (N)


From the Image Gallery

6 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Breeding System: Flowers Bisexual
Fruit Type: Drupe
Size Notes: Leaves float on the surface of the water. Flower spikes rise up to about 6 inches above the surface of the water.
Leaf: Green
Fruit: Drupaceous.

Bloom Information

Bloom Color: White , Green
Bloom Time: May , Jun , Jul , Aug , Sep , Oct


USA: AL , AR , AZ , CA , CO , CT , DC , DE , FL , GA , HI , IA , ID , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , MT , NC , ND , NE , NH , NJ , NM , NV , NY , OH , OK , OR , PA , RI , SC , SD , TN , TX , UT , VA , VT , WA , WI , WV , WY
Canada: NB , NS
Native Habitat: Partial to marginal to deepwater aquatic areas. Zones 7 - 11, with an indefinite range.

Growing Conditions

Water Use: High
Light Requirement: Sun , Part Shade
Soil Moisture: Wet
CaCO3 Tolerance: Low
Aquatic: yes
Conditions Comments: Use as oxygenator in water gardens. The variety P. crispus tolerates polluted water better than other oxygenators. Decorative, trailing habit in ponds. Grow in aquatic containers of sandy loam, root in muddy pool bottoms at depth of 6" - 24".


Interesting Foliage: yes
Deer Resistant: High

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Lady Bird Johnson Wildflower Center - Austin, TX


Bibref 841 - Native Alternatives to Invasive Plants (2006) Burrell, C. C.

Search More Titles in Bibliography

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Potamogeton nodosus in USDA Plants
FNA: Find Potamogeton nodosus in the Flora of North America (if available)
Google: Search Google for Potamogeton nodosus


Record Modified: 2023-02-23
Research By: NPC

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