Ludwigia octovalvis
Mexican primrose-willow
Overview
Ludwigia octovalvis is an erect, willow-like perennial or soft-wooded subshrub in the Onagraceae, growing 1.5-6 feet (0.5-1.8 m) tall on reddish, ridged, often much-branched stems. The narrow, lance-shaped leaves are 1-4 inches (2.5-10 cm) long and taper to a point, resembling those of a willow. Throughout the warm season it produces solitary yellow flowers in the leaf axils, each with four broad petals about 0.4-0.8 inch (10-20 mm) across. The flowers develop into elongated, eight-ribbed seed capsules 1-2 inches (2.5-5 cm) long (the source of the name octovalvis) that release many tiny seeds. It grows in marshes, ditches, pond edges, wet roadsides, and flooded rice fields throughout the tropics and subtropics worldwide, where it can become a weed of waterlogged ground. Plants root readily at the lower nodes and spread by both seed and stem fragments. In frost-free regions it can persist for several years, but it is killed by frost and behaves as an annual at the cool margins of its range. Growth is rank and open rather than dense.
Native Range
Considered native to the tropical Americas and now found throughout the tropics and subtropics of the world, including the southern United States, Mexico, Africa, and Asia. It grows in marshes, ditches, pond margins, and other wet, open ground.Suggested Uses
Ludwigia octovalvis is used in pond margins, bog gardens, and constructed wetlands in warm climates, and is studied for water treatment because it takes up nutrients from polluted water. Its willow-like form suits naturalistic wet plantings. In many regions it is managed as a weed of canals and rice fields rather than grown ornamentally.How to Identify
Appearance
Size & Dimensions
Height1'6" - 6'
Width/Spread1' - 3'
Bloom Information
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Ludwigia octovalvis grows in full sun on wet, mucky, or saturated soils and tolerates standing water and seasonal flooding. It needs constant moisture and does not survive in dry ground. In frost-free climates it persists as a short-lived perennial; where winters are cold it is killed by frost and regrows from seed. It roots easily from stem cuttings pressed into wet soil. The plant self-sows freely in damp, open sites and can spread aggressively in still or slow water. It needs no fertilizer in fertile wetland soils.Pruning
Cut stems back at any time to limit height and spread, since the plant regrows quickly from the base. Removing seed capsules before they ripen reduces self-sowing in and around water.Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons