The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Ludwigia grandiflora
Ludwigia grandiflora
(large-flower primrose-willow)

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Ludwigia grandiflora (Michx.) Greuter & Burdet

Common name: large-flower primrose-willow

Synonyms and Other Names: Ludwigia grandiflora ssp. grandiflora, Ludwigia uruguayensis, Jussiaea grandiflora

Taxonomy: available through www.itis.govITIS logo

Identification: According to Godfrey and Wooten (1981):

Habit: Perennial, floating and emergent, herbaceous forb

Stem/roots: non-flowering, sprawling stems float along the water surface with roots at the stem nodes; upright stems freely branching and flowering; pubescent

Leaves: alternating leaves on floating stems are spatulate (spoon-shaped), petiolate (leaf stems), and have rounded apices; alternating leaves on upright stems are lanceolate (lance-shaped), mostly sessile, and have acute apices; pubescent

Flowers: solitary flowers at leaf axils of upright stems; pedicels 1-5 cm, usually confused with floral tubes; a pair of small bractlets indicate the separation of the pedicel and floral tube; pedicel and floral tube pubescent; calyx of 5, sometimes 6, acute sepals, 10-12 mm, pubescent on the outside; corolla of 5, sometimes 6, bright yellow, rounded petals, 1-2 cm long and wide; stamens 8-12, twice the amount of sepals/petals

Fruits: fruit a pubescent, cylindric capsule 1-2.5 cm long, 3-4 mm wide

Look-alikes: Many Ludwigia species have similar leaves and flowers, but those two organs are key to determining identity. The alternate leave arrangement, the 8-12 stamens, and the 5-6 petals differentiate to about four species. The Ludwigia uruguayensis species complex includes L. grandiflora and L. hexapetala. Leaves on upright stems will be mostly lanceolate (widest portion of the leaf in the leaf center) on L. grandiflora and mostly oblanceolate (widest portion of the leaf in the top half of the leaf) on L. hexapetala, and stem nodes are swollen along the lower portion of upright stems on L. hexapetala (Colette Jacono, Univ. of Florida, pers. comm. 2017). Upright stems of L. grandiflora have pubescent stems, leaves, and floral tubes, distinguishing them from L. peploides, which are mostly glabrous (hairless) and lack upright stems. Floral tubes/capsules of L. grandiflora are narrower and longer than those of L. peruviana, which have stout and pyramidal floral tubes/capsules. The native L. leptocarpa has smaller petals (<1 cm) than those of L. grandiflora (>1 cm), usually the same length as the sepals.

Size: 23 m wide patches on water surface (Les 2018)

Native Range:
Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Ludwigia grandiflora are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AL198819881Upper Black Warrior
AR198820157Arkansas-White-Red Region; Bodcau Bayou; Lower Little Arkansas, Oklahoma; Lower Ouachita-Bayou De Loutre; Lower Sulpher; Upper Beaver; Upper Saline
CA194020188Lower Klamath; Russian; San Diego; San Francisco Bay; Santa Clara; Santa Margarita; Tomales-Drake Bays; Upper Putah
DE199319952Brandywine-Christina; Broadkill-Smyrna
FL197220203Kissimmee; Santa Fe; Sarasota Bay
GA198720202Lower Chattahoochee; Lower Flint
KY198820112Lower Cumberland; Red
LA1983201921Atchafalaya; Atchafalaya - Vermilion; Bayou Teche; Boeuf; Boeuf-Tensas; Calcasieu-Mermentau; East Central Louisiana Coastal; Eastern Louisiana Coastal; Lake Maurepas; Lake Maurepas; Lower Calcasieu; Lower Mississippi; Lower Mississippi Region; Lower Mississippi-New Orleans; Lower Ouachita; Lower Red-Ouachita; Lower Sabine; Mermentau; Vermilion; West Central Louisiana Coastal; West Fork Calcasieu
MD201120172Chincoteague; Middle Potomac-Anacostia-Occoquan
MS198220195Deer-Steele; Escatawpa; Luxapallila; Mississippi Coastal; Upper Tombigbee
MO199719971Lower Osage
NC196620194Contentnea; Haw; Lower Cape Fear; Upper Tar
OK198119811Arkansas-White-Red Region
OR194920185Applegate; Lower Columbia-Clatskanie; Lower Rogue; Siuslaw; Upper Willamette
PA194119772Lower Delaware; Schuylkill
SC1938201913Broad-St. Helena; Cooper; Lake Marion; Lower Broad; Lower Catawba; Lower Savannah; North Fork Edisto; Salkehatchie; Saluda; South Carolina Coastal; Tyger; Upper Broad; Wateree
TN196819882Lower Cumberland; Lower Cumberland-Sycamore
TX193520227Llano; Lower Brazos; Lower Neches; Lower Trinity; Middle Neches; Pine Island Bayou; Sabine Lake
VA199019972Potomac; Powell
WA199520052Duwamish; Lower Columbia-Clatskanie

Table last updated 6/13/2024

† Populations may not be currently present.

* HUCs are not listed for states where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).


Life history: self-compatible flowers will self-fertilize; most reproduction is through vegatative fragmentation of stems; flowers from April to September; seeds remain embedded in woody capsules (Okada et al. 2009; Les 2018)

Habitat: marshes, swamps, ponds, lakes, ditches, canals, and wet disturbed areas (Godfrey and Wooten 1981; Les 2018)

Tolerances: fresh to brackish (0-3.5 ppt salinity); pH 6.1-7.3; depths to 2.4 m; elevations to 102 m; poorly drained muck and sandy clay; fire-, flood-, graze-, and mow- tolerant over short periods (Les 2018)

Community interactions: pollinated by generalists (bees, butterflies, and flowerflies); waterfowl consume the seeds of L. grandiflora; Lysathia ludoviciana leaf beetles consume the foliage of L. grandiflora (Les 2018)

Means of Introduction: The primary introduction pathway is through the ornamental plant trade (Jacono 2014). Secondarily L. grandiflora is dispersed as stem fragments carried by water and waterfowl (Les 2018).

Impact of Introduction:
Summary of species impacts derived from literature review. Click on an icon to find out more...

EcologicalEconomicHuman HealthOther

Ecological impacts

Ludwigia grandiflora creates large homogenous mats that outcompete other organisms for essential resources, such as light, nutrients, and open water habitat for waterfowl (Nehring and Kolthoff 2011, Stiers et al. 2011, Grewell et al. 2016). Invertebrate richness and abundance declined in ponds with high abundance of L. grandiflora due to increased decomposition and decreased dissolved oxygen (Stiers et al. 2011). However, pollinator densities increased in communities with L. grandiflora, but native plant species richness, especially submerged plants, declined due to decreased sunlight availability and oxygen exchange (Stiers et al. 2011, Stiers et al. 2014). Through allelopathic chemicals, L. grandiflora inhibited Lactuca sativa and Nasturtium officinale germination when grown in mixtures (Dandelot et al. 2008).

References: (click for full references)

Dandelot, S., C. Robles, N. Pech, A. Cazaubon, and R. Verlaque. 2008. Allelopathic potential of two invasive alien Ludwigia spp. Aquatic Botany 88:311-316.

Godfrey, R.K., and J.W. Wooten. 1981. Aquatic and Wetland Plants of the Southeastern United States, dicotyledons. University of Georgia, Athens, GA.

Grewell, B.J., M.D. Netherland, and M.J. Skaer Thomason. 2016. Establishing research and management priorities for invasive water primroses (Ludwigia spp.). U.S. Army Corps of Engineers, Engineer Research and Development Center, Vicksburg, MS. https://apps.dtic.mil/sti/pdfs/AD1002917.pdf.

Les, D.H. 2018. Aquatic dicotyledons of North America: ecology, life history, and systematics. CRC Press, Boca Raton, FL.

Nehring, S. and D. Kolthoff. 2011. The invasive water primrose Ludwigia grandiflora (Michaux) Greuter & Burdet (Spermatophyta: Onagraceae) in Germany: First record and ecological risk assessment. Aquatic Invasions 6(1):83–89. https://doi.org/10.3391/ai.2011.6.1.10.

Nesom, G.L. and J.T. Kartesz. 2000. Observations on the Ludwigia uruguayensis complex (Onagraceae) in the United States. Castanea. 65(2): 123-125.

Okada, M., B. Grewell, M. Jasieniuk. 2009. Clonal spread of invasive Ludwigia hexapetala and L. grandiflora in freshwater wetlands of California. Aquatic Botany 91:123-129.

Stiers, I., N. Crohain, G. Josens, and L. Triest. 2011. Impact of three aquatic invasive species on native plants and macroinvertebrates in temperate ponds. Biological Invasions 13:2715-2726. https://doi.org/10.1007/s10530-011-9942-9.

Stiers, I., K. Coussement, and L, Triest. 2014. The invasive aquatic plant Ludwigia grandiflora affects pollinator visitants to a native plant at high abundances. Aquatic Invasions 3:357-367.

Wagner, W.L., P.C Hoch and P.H. Raven 2007. Systematic Botany Monographs: Revised Classification of the Onagraceae. 83: 243 pp.

Zardini, E. M., H. Gu & P. H. Raven 1991. On the separation of two species within the Ludwigia uruguayensis complex (Onagraceae). Systematic Botany. 16(2): 242–244.

Zardini, E.M., H. Gu, and P.H. Raven. 1992. Erratum: on the separation of two species within the Ludwigia uruguayensis complex (Onagraceae). Systematic Botany. 17(4): 692.

Author: Pfingsten, I., and K.M. Reaver

Revision Date: 11/2/2021

Citation Information:
Pfingsten, I., and K.M. Reaver, 2024, Ludwigia grandiflora (Michx.) Greuter & Burdet: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=253, Revision Date: 11/2/2021, Access Date: 6/13/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


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Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/13/2024].

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