Heteranthera dubia
Water star-grass, Water Star-Grass
(c) Laura Gaudette, some rights reserved (CC BY), uploaded by Laura Gaudette · licence
Family: Pontederiaceae · Type: Herb · Native
Conservation status: CNPS 2B.2
Heteranthera dubia (Water star-grass) is a native California herb in the Pontederiaceae family, recognized by . Key differences: growth form (submersed vs emergent), leaf shape, habitat preference, native status.
Water star-grass is a native perennial found in northern California Coast, Sacramento Valley, and North Coast Ranges in still or moving water habitats at elevations below 1,500 meters. Flowering from July to August, this aquatic plant produces delicate yellow flowers on stems that emerge above the water surface. Growing as a submersed perennial herb that often roots at its nodes, it develops slender stems that can extend beyond 15 centimeters in length. Its leaves are elongated and emerge predominantly underwater, creating a graceful presence in aquatic environments. When in bloom, the plant displays a distinctive perianth tube up to 1.5 centimeters long with three symmetrical stamens that add to its subtle beauty.
Identification and appearance
Key characters: 1 sympatric species. Key differences: growth form (submersed vs emergent), leaf shape, habitat preference, native status
Habitat and range
Habitat: Uncommon. Still or moving water
Elevation: < 1500 m
Outside California: North America
Bloom period
Heteranthera dubia blooms Jul-Aug.
Conservation status
CNPS 2B.2
How to tell it apart
vs Eichhornia: Heteranthera has thin petioles and single flowers; Eichhornia has balloon-like leaf stalks and flower clusters.; vs Monochoria: Heteranthera has three stamens and long trumpet flowers; Monochoria has six stamens and short bell-shaped flowers.; vs Commelina: Heteranthera is aquatic with parallel-veined leaves; Commelina is terrestrial with broader net-veined leaves.; vs Pectocarya: Heteranthera is aquatic with trumpet flowers; Pectocarya is terrestrial with tiny white flowers and nutlets.; vs Viola: Heteranthera has symmetrical trumpet flowers in water; Viola has irregular spurred flowers on land.
Frequently asked questions
Is Heteranthera dubia native to California?
Yes. Heteranthera dubia is native to California (recorded as native).
When does Heteranthera dubia bloom?
Heteranthera dubia blooms Jul-Aug.
What plant family does Heteranthera dubia belong to?
Heteranthera dubia is in the Pontederiaceae family, genus Heteranthera.
Is Heteranthera dubia rare or endangered?
Heteranthera dubia carries California Rare Plant Rank 2B.2, state rank S2.
What habitat does Heteranthera dubia grow in?
Heteranthera dubia grows in Uncommon. Still or moving water.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
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.