[2] This species is an annual herb that reaches up to 6 feet (1.8 m) tall, sometimes growing as a perennial by virtue of its partially woody stem.

[5] This plant grows in wet habitat types, often alongside Polygonum and Cyperus species.

[2] L. decurrens has become an invasive species in Africa and in Southeast Asia, where it frequently colonizes rice paddies and other wetlands.

[5] Invasion in anaerobic habitats is facilitated by the aerenchyma that enable willow primrose rhizomes to float and by its capacity to spread either by seed or by vegetative propagation from broken plant fragments.

[5] Exudates from this species have been shown to have allelopathic effects on Corchorus olitorius by increasing mortality of seedlings.