creeping primrose
Family
OnagraceaeScientific Name
Ludwigia palustrisOther Common Names:
marsh seedbox
Synonyms (former Scientific Names):
Isnardia palustris
Ludwigia palustris var. pacifica
Ludwigia palustris var. americana
Ludwigia palustris var. nana
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.
Growth Habit
upright and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
quarter
Dominant Flower Color
yellow
Flower Symmetry
radial symmetery
Leaf Hairs
Varies:
has hairs,
no hairs
Leaf Shape
Varies:
lance,
oval
Leaf Arrangement
opposite
Leaf Margin
entire
Leaf Structure
simple
Leaf Stalk
shorter than leaf
Stem Hairs
Varies:
has hairs,
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
fibrous
Life Cycle
perennial
Ochrea
not present
Plant Type
Herb