Ludwigia grandiflora
uruguayan primrosewillow, uruguayan primrose-willow, water primrose, uruguay waterprimrose, large-flower primrose-willw
Family
Onagraceae
Leaf Arrangement
alternate
Leaf Attachment
petiolate
Leaf Margin
entire
Leaf Type
simple
Leaf Shape
elliptic, oblanceolate, obovate, spatulate
Growth Form
forb, shrub, floating aquatic, aquatic
Flower Color
yellow
Flower Petals
5, 6
Flower Month
May - October
Height (meters)
0.2 - 1.0
Milky Sap
No
Armed/Unarmed
Unarmed
Origin
introduced
Lifespan
perennial
Growing Season
Warm season
Wetland Class
OBL
Prairie Coefficient of Conservatism
-2
Field Characters
Matt forming with large 5 (6) petaled yellow flowers. Long shaggy hair on stems. Lower stem creeping and rooting at the nodes. Capsules 1-2.5 cm long and hairy.
Cultural Information
Clonal expansion is the primary means of reproduction for the species. Stem fragments are spread by animals, humans, and water currents. Most populations flower, but sexual reproduction is likely of lesser importance than vegetative reproduction.
Natural History
An exotic that often forms large floating mats in still water.
Habitat
Slow streams, pools, and marshes, wet places alongside ponds, ditches.