Jepson eFlora: Taxon page
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Ludwigia palustris

Higher Taxonomy
Family: OnagraceaeView DescriptionDichotomous Key

Habit: Annual to perennial herb (to tree). Leaf: cauline or basal, alternate, opposite, or whorled, generally simple and toothed (to pinnately compound); stipules 0 or generally deciduous. Inflorescence: spike, raceme, panicle, or flowers 1 in axils; bracted. Flower: generally bisexual, generally radial, often opening at either dawn or dusk; hypanthium generally prolonged beyond ovary (measured from ovary tip to sepal base); sepals 4(2--7); petals 4(2--7, rarely 0), often fading darker; stamens 2 × or = sepals in number, anthers 2-chambered, opening lengthwise, pollen interconnected by threads; ovary inferior, chambers generally as many as sepals (sometimes becoming 1), placentas axile or parietal, ovules 1--many per chamber, style 1, stigma 4-lobed (or lobes as many as sepals), club-shaped, spheric, or hemispheric. Fruit: capsule, loculicidal (sometimes berry or indehiscent and nut-like). Seed: sometimes winged or hair-tufted.
Genera In Family: 22 genera, +- 657 species: worldwide, especially western North America; many cultivated (Clarkia, Epilobium, Fuchsia, Oenothera). Note: Gaura moved to Oenothera. Fuchsia magellanica Lam. naturalized in northern California.
eFlora Treatment Author: Warren L. Wagner & Peter C. Hoch, family description, key to genera; treatment of genera by Warren L. Wagner, except as noted
Scientific Editor: Robert Patterson, Bruce G. Baldwin.
Genus: LudwigiaView DescriptionDichotomous Key

Habit: Annual to subshrub or emergent aquatic, often floating, rooting at nodes. Leaf: alternate to opposite. Inflorescence: spike; flowers 1 per bract. Flower: radial; hypanthium 0; sepals 4--5(7), persistent; petals (0)4--5(7), white to yellow; stamens 4 or 10(12), pollen generally shed singly (in California); stigma club-shaped to spheric. Fruit: irregularly dehiscing; wall thick or thin. Seed: free or embedded in woody piece of fruit wall.
Species In Genus: 82 species: +- worldwide. Etymology: (C.G. Ludwig, German botanist, physician, 1709--1773) Note: Many polyploids.
eFlora Treatment Author: Peter C. Hoch & Brenda J. Grewell

Ludwigia palustris (L.) Elliott
Habit: Perennial herb 1--5 dm, matted. Stem: prostrate or ascending, rooting at nodes, well branched, +- glabrous. Leaf: opposite, < 5 cm; blade narrowly elliptic to subovate, entire, +- glabrous. Inflorescence: pedicel 0--0.5 mm. Flower: sepals 4, 1.1--2 mm; petals 0; stamens 4, anthers 0.2--0.4 mm; ovary stripes 4, green. Fruit: erect, 1.5--5 mm, +- oblong, minutely strigose. Seed: 0.5--0.7 mm, free from fruit wall. Chromosomes: 2n=16.
Ecology: Roadside ditches, wet meadows, pond margins; Elevation: < 1000 m. Bioregional Distribution: w NW, n SN, c SNH, SnJV, CCo, SnFrB, SCo; Distribution Outside California: to British Columbia, eastern United States, Central America, northern South America; introduced +- worldwide. Flowering Time: Jun--Sep Note: Highly variable, often weedy.
Synonyms: Ludwigia palustris var. americana (DC.) Fernald & Griscom; Ludwigia palustris var. pacifica Fernald & Griscom
eFlora Treatment Author: Peter C. Hoch & Brenda J. Grewell
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botanical illustration including Ludwigia palustris


Citation for this treatment: Peter C. Hoch & Brenda J. Grewell 2016. Ludwigia palustris, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on May 04, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on May 04, 2016.

Ludwigia palustris
click for enlargement
© 2008 Keir Morse
Ludwigia palustris
click for enlargement
© 2008 Keir Morse

More photos of Ludwigia palustris in CalPhotos

Geographic subdivisions for Ludwigia palustris:
w NW, n SN, c SNH, SnJV, CCo, SnFrB, SCo;
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.