E-Flora BC: Electronic Atlas of the Flora of British Columbia

Ludwigia palustris (L.) Elliott
water-purslane (marsh seedbox)
Onagraceae (Evening Primrose family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #4197)

E-Flora BC Static Map
Distribution of Ludwigia palustris
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Species Information

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Perennial herb, floating or matted; stems prostrate or ascending, 10-50 cm long, rooting at nodes, well branched, succulent, glabrous.
Opposite, narrowly elliptic or egg-shaped, 2-6 cm long, tapered gradually to broad stalks that are about same length, entire.
Inflorescence of several pairs of unstalked flowers, 1 flower per axil of upper leaves; petals lacking; sepals 4, egg-shaped, about 2 mm long, greenish, persistent; stamens 4; anthers 0.2-0.4 mm long, longer than filaments; stigmas globe-shaped.
Capsules, 2.5-4 mm long, 4-sided, oblong, top-shaped above, with 2 tiny bracts at base; seeds numerous, glabrous, 0.5-0.7 mm long.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Yellow
Present from Summer to Fall
Source:  The USDA

Habitat / Range

Wet streamsides and lakeshores in the lowland zone; infrequent on S Vancouver Island and the lower Fraser valley; E to NB and S to FL and MX; Africa, Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Ludwigia palustris

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
Slope Gradient (%)
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: CWH(3)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is cool mesothermal.

Synonyms and Alternate Names

Isnardia palustris L., non Jussiaea palustris G. Mey.
Ludwigia palustris var. americana (DC.) Fernald & Grisc.
Ludwigia palustris var. nana Fernald & Grisc.
Ludwigia palustris var. pacifica Fernald & Grisc.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References