Ludwigia grandiflora
Large-flowered primrose-willow
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Family: Onagraceae · Type: Subshrub · Not Native
Ludwigia grandiflora (Large-flowered primrose-willow) is a non-native California subshrub in the Onagraceae family, recognized by . Large flowers (15-18mm petals).
Large-flowered primrose-willow is a naturalized perennial found in southern California coastal and peninsula regions on streambanks and shores at elevations below 300 meters. Flowering from May to November, this plant produces yellow flowers 15 to 18 millimeters long with distinctive large petals. Growing with prostrate to erect stems 140 to 310 centimeters tall, occasionally developing thick white spongy roots at floating nodes, it spreads across wet habitats with remarkable adaptability. Its alternate leaves range from narrowly elliptic to widely obovate, 3 to 10 centimeters long, with hairy midribs and entire edges. The fruit is cylindric, 13 to 25 millimeters long, generally reflexed and falling with its pedicel.
Identification and appearance
Key characters: 5 sympatric species. Large flowers (15-18mm petals) are diagnostic.
Habitat and range
Habitat: Streambanks, shores
Elevation: < 300 m
Outside California: southeastern and southern United States, Central America (native?), southern South America
Bloom period
Ludwigia grandiflora blooms May-Nov.
How to tell it apart
vs Veronica: Ludwigia flowers have 4-5 petals and persistent sepals; Veronica has 4 petals and sepals that fall off.; vs Pistia: Ludwigia has separate petals and normal leaves; Pistia is a free-floating rosette with a spathe-like flower.; vs Portulaca: Ludwigia grows in wet habitats with thin leaves; Portulaca has succulent, fleshy leaves in dry areas.; vs Alternanthera: Ludwigia has slender stems; Alternanthera stems are distinctly swollen at the nodes.; vs Epilobium: Ludwigia flowers have no floral tube; Epilobium has a distinct tubular hypanthium extending above the ovary.
Frequently asked questions
Is Ludwigia grandiflora native to California?
No. Ludwigia grandiflora is not native to California (recorded as not native).
When does Ludwigia grandiflora bloom?
Ludwigia grandiflora blooms May-Nov.
What plant family does Ludwigia grandiflora belong to?
Ludwigia grandiflora is in the Onagraceae family, genus Ludwigia.
What habitat does Ludwigia grandiflora grow in?
Ludwigia grandiflora grows in Streambanks, shores.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-08
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.