Scientific Name: Ludwigia palustris

Common Name: creeping primrose

Other Common Names: marsh seedbox

Synonyms: Isnardia palustris, Ludwigia palustris var. americana, Ludwigia palustris var. nana, Ludwigia palustris var. pacifica

Habit: A creeping aquatic weed that grows along shorelines, in shallow water, and less often submersed in shallow water.

Leaves: Arranged oppositely along the stem, oval-shaped/lanceolate, approximately 1/2 to 1 inch long. The leaves of creeping primrose are highly variable in color, from green to slightly red-tinged or entirely red- or purple-tinged. Leaves are without hairs (glabrous). Stems are creeping and rooting at the nodes.

Identifying Characteristics: Aquatic plant primarily of shorelines with opposite leaves and stems that root at the nodes. Additionally, the red- or purple-tinged leaves that sometimes occur help in the identification of creeping primrose. Several other primrose species occur as aquatics. Creeping primrose is the species most commonly encountered, however. The plant may create bladders/air pockets to keep the plant floating.

Flower Seed Head: Arise from the areas between the stems and the leaves (leaf axils) and are inconspicuous and without petals. The flowers are usually yellow with 5 petals and sepals and not too close to other flowers and ~1in (25mm) in diameter.

Seed Fruit: Seed capsules are around an inch long and contain 5 cells with rows of seeds (~1mm).

Where Found: Coastal areas and ponds.

  • Life cycle: perennial

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Onagraceae

  • Leaf arrangement: opposite

  • Leaf shape: lance; oval

  • Ochrea: Not Present

  • Leaf margin: entire

  • Stem hairs: has hairs; no hairs

  • Flower color: yellow

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs; no hairs

  • Flower diameter: quarter

  • Flower symmetry: radial symetery

  • Root structure: fibrous

  • Leaf stalk: shorter than leaf