Lemna trisulca
Ivy leaved duckweed
(c) Michael D. Pirie, some rights reserved (CC BY) · licence
Family: Araceae · Type: Herb · Native
Lemna trisulca (Ivy leaved duckweed) is a native California herb in the Araceae family, recognized by uniquely forms branched chains and is lanceolate rather than elliptic.
Ivy leaved duckweed is a native aquatic perennial found in northern California, the Sierra Nevada, Sacramento Valley, San Bernardino Mountains, Great Basin, Modoc Plateau, and Mojave Desert in mountain streams and meadows at elevations below 3,000 meters. Flowering in August, this delicate aquatic plant produces minimal flowers typical of its duckweed family. Growing in transparent green, lanceolate to oblong segments 6 to 10 millimeters long, it often forms branched chains of 8 to 30 interconnected plants. Its plant body is distinctive for its tapered stalk and symmetric base and tip, creating a unique floating structure. With essentially no roots, this duckweed moves gracefully across water surfaces in mountain habitats.
Identification and appearance
Key characters: Co-occurs with 6 species; uniquely forms branched chains and is lanceolate rather than elliptic
Habitat and range
Habitat: Meadows, mountain streams
Elevation: < 3000 m
California counties: Orange, San Bernardino, Plumas, Tulare, Mono, Colusa, Inyo, Butte, Modoc, Lassen, Madera, Kern, San Luis Obispo, Alpine, Nevada, Placer, Humboldt, Trinity, Tehama, Napa, Lake, Merced
Outside California: +- worldwide.
Bloom period
Lemna trisulca blooms Aug.
How to tell it apart
vs Azolla: Lemna is smooth bright green with a single root; Azolla is feathery textured, often reddish, with no visible roots.; vs Callitriche: Lemna floats as separate tiny discs; Callitriche has distinct stems with opposite leaves forming small rosettes.; vs Nasturtium: Lemna is a tiny rootless-looking disc; Nasturtium has obvious stems, compound leaves, and grows rooted in mud.; vs Spirodela: Count the roots: Lemna has exactly one root per disc, Spirodela has multiple roots clustered together beneath each disc.; vs Landoltia: Count the roots: Lemna has one root per disc, Landoltia has 2-7 roots hanging down like a tiny broom.
Frequently asked questions
Is Lemna trisulca native to California?
Yes. Lemna trisulca is native to California (recorded as native).
When does Lemna trisulca bloom?
Lemna trisulca blooms Aug.
Where in California does Lemna trisulca grow?
Lemna trisulca occurs in Orange, San Bernardino, Plumas, Tulare, Mono, Colusa, Inyo, Butte and other counties, at elevations of < 3000 m.
What plant family does Lemna trisulca belong to?
Lemna trisulca is in the Araceae family, genus Lemna.
What habitat does Lemna trisulca grow in?
Lemna trisulca grows in Meadows, mountain 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.