Potamogeton amplifolius
Broad-leaved pondweed
(c) Nathan Aaron, some rights reserved (CC BY) · licence
Family: Potamogetonaceae · Type: Herb · Native
Potamogeton amplifolius (Broad-leaved pondweed) is a native California herb in the Potamogetonaceae family, recognized by extremely broad leaves and folded/curved leaf posture distinctive.
Broad-leaved pondweed is a California native perennial found in northern California Coast Ranges, high Cascade Range, Sierra Nevada, and Warner Mountains in deep, clear-water lakes at elevations of 600 to 1,850 meters. Flowering from July to August, this aquatic plant produces small flowers in compact inflorescences less than 5 centimeters long. Growing with stout rhizomes and stems up to 90 centimeters tall, it creates distinctive underwater vegetation with cylindrical branches. Its submersed leaves are particularly striking, measuring 8 to 20 centimeters long and 2 to 7 centimeters wide, typically lanceolate to ovate, often folded along the midvein and curved backward with 19 to 50 distinct veins. The plant develops fibrous, stringy stipules and distinctive floating leaves that are elliptic to ovate, 5 to 10 centimeters long with 27 to 50 veins.
Identification and appearance
Key characters: 15 sympatric species; extremely broad leaves and folded/curved leaf posture distinctive
Habitat and range
Habitat: Uncommon. Deep, clear-water lakes
Elevation: 600-1850 m
Outside California: to British Columbia, eastern North America
Bloom period
Potamogeton amplifolius blooms Jul-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 amplifolius native to California?
Yes. Potamogeton amplifolius is native to California (recorded as native).
When does Potamogeton amplifolius bloom?
Potamogeton amplifolius blooms Jul-Aug.
What plant family does Potamogeton amplifolius belong to?
Potamogeton amplifolius is in the Potamogetonaceae family, genus Potamogeton.
What habitat does Potamogeton amplifolius grow in?
Potamogeton amplifolius grows in Uncommon. Deep, clear-water lakes.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.