Alisma lanceolatum
Lanceleaf water plantain
(c) Samuel A Schmid, PhD, PWS, some rights reserved (CC BY) · licence
Family: Alismataceae · Type: Herb · Not Native
Alisma lanceolatum (Lanceleaf water plantain) is a non-native California herb in the Alismataceae family, recognized by pink petals and tapered leaf base diagnostic.
Lanceleaf water plantain is a naturalized perennial found in northwestern California, northern Sierra Nevada foothills, and Sacramento Valley in ponds, rice fields, and slow streams at elevations below 500 meters. Flowering from summer to fall, this plant produces distinctive pink flowers with petals that are partially cut. Growing with long leaves 12 to 40 centimeters in length, it has lanceolate blades 6 to 12 centimeters long and 1 to 3 centimeters wide that taper at the base. Its inflorescence typically grows taller than the leaves, with pedicels ascending to erect. The fruits have thin, translucent lateral walls, contributing to the plant's delicate appearance.
Identification and appearance
Key characters: 1 sympatric species; pink petals and tapered leaf base diagnostic
Habitat and range
Habitat: Ponds, rice fields, slow streams
Elevation: < 500 m
California counties: Sonoma, Butte, Shasta, Los Angeles, Sutter, Nevada, Colusa, Marin, Placer, Solano, Tehama, Yuba, Mendocino, Lassen, Contra Costa, Yolo
Outside California: Oregon, Chile, Australia, native to Eurasia, northern Africa
Bloom period
Alisma lanceolatum blooms Summer-fall.
How to tell it apart
vs Echinodorus: Alisma fruits sit flat in a ring; burhead fruits spiral on a dome forming a bur.; vs Sagittaria: Alisma flowers have both male and female parts; arrowhead has separate male and female flowers.; vs Rumex: Alisma has three white petals and aquatic habit; dock has tiny greenish flowers and terrestrial habit.; vs Potamogeton: Alisma has three white petals above water; pondweed has tiny flowers and submerged leaves.; vs Plantago: Alisma has three distinct white petals; plantain has tiny four-part flowers in dense brown spikes.
Frequently asked questions
Is Alisma lanceolatum native to California?
No. Alisma lanceolatum is not native to California (recorded as not native).
When does Alisma lanceolatum bloom?
Alisma lanceolatum blooms Summer-fall.
Where in California does Alisma lanceolatum grow?
Alisma lanceolatum occurs in Sonoma, Butte, Shasta, Los Angeles, Sutter, Nevada, Colusa, Marin and other counties, at elevations of < 500 m.
What plant family does Alisma lanceolatum belong to?
Alisma lanceolatum is in the Alismataceae family, genus Alisma.
What habitat does Alisma lanceolatum grow in?
Alisma lanceolatum grows in Ponds, rice fields, slow 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.