Potamogeton nodosus
Long-leaved pondweed
(c) Марина Садыкова, some rights reserved (CC BY), uploaded by Марина Садыкова · licence
Family: Potamogetonaceae · Type: Herb · Native
Potamogeton nodosus (Long-leaved pondweed) is a native California herb in the Potamogetonaceae family, recognized by very long narrow submersed leaves plus long-petioled floating leaves distinctive.
Long-leaved pondweed is a native perennial found in diverse regions including northern California Coast Ranges, Sierra Nevada, Central Valley, Central Coast, San Francisco Bay Area, Southern California, San Bernardino Mountains, Peninsular Ranges, Great Basin, and Mojave Desert in shallow water habitats such as lakes, ponds, and streams at elevations of 100 to 2,750 meters. Flowering from May to August, this aquatic plant produces small, inconspicuous greenish flowers along slender underwater inflorescences less than 5 centimeters long. Growing with branching rhizomatous stems up to 3 meters in length, it develops both submerged and floating leaves with distinctive characteristics. Its underwater leaves are linear to lance-elliptic, 2 to 15 centimeters long and 10 to 40 millimeters wide, while floating leaves are elliptic to ovate, 5 to 10 centimeters long with 9 to 21 visible veins. The fruit is small, 3 to 5 millimeters long, with three distinct keels and flat sides.
Identification and appearance
Key characters: 14 sympatric species; very long narrow submersed leaves plus long-petioled floating leaves distinctive
Habitat and range
Habitat: Shallow water, lakes, ponds, streams
Elevation: 100-2750 m
California counties: Humboldt, Orange, San Diego, Fresno, Mono, Santa Cruz, Tuolumne, San Mateo, Inyo, Mendocino, Modoc, San Bernardino, Tulare, Lake, Kern, Marin, Butte, Los Angeles, Ventura, Shasta, San Luis Obispo, Sonoma, Alameda, Alpine, Glenn, Merced, Monterey, Nevada, San Joaquin, Santa Clara, Yuba, Plumas, Imperial, Tehama, Lassen, Solano, Stanislaus, Madera, Yolo, Siskiyou, Trinity, El Dorado, Riverside, Del Norte, Sierra, Colusa, Napa
Outside California: worldwide (except Australia)
Bloom period
Potamogeton nodosus blooms May-Aug.
How to tell it apart
vs Persicaria: Potamogeton flowers float on water; Persicaria has terrestrial pink/white flower spikes above solid ground.; vs Stuckenia: Potamogeton flowers emerge above water on stiff stalks; Stuckenia flowers stay underwater on flexible stalks.; vs Alisma: Potamogeton has inconspicuous spike flowers; Alisma has showy white three-petaled flowers in branched clusters.; vs Ranunculus: Potamogeton has tiny greenish spike flowers; Ranunculus has bright yellow buttercup flowers with visible petals.; vs Myriophyllum: Potamogeton has broad or ribbon-like leaves; Myriophyllum has feathery, finely divided leaves like a bottlebrush.
Frequently asked questions
Is Potamogeton nodosus native to California?
Yes. Potamogeton nodosus is native to California (recorded as native).
When does Potamogeton nodosus bloom?
Potamogeton nodosus blooms May-Aug.
Where in California does Potamogeton nodosus grow?
Potamogeton nodosus occurs in Humboldt, Orange, San Diego, Fresno, Mono, Santa Cruz, Tuolumne, San Mateo and other counties, at elevations of 100-2750 m.
What plant family does Potamogeton nodosus belong to?
Potamogeton nodosus is in the Potamogetonaceae family, genus Potamogeton.
What habitat does Potamogeton nodosus grow in?
Potamogeton nodosus grows in Shallow water, lakes, ponds, streams.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.