Perennial herb. Large leathery floating green leaves <40cm x 30cm, lettuce-like submerged leaves. Forms large, spongy rhizomes. Bright yellow flowers smelling strongly of alcohol above surface. Green flask shaped fruit split open to release seeds.
Still or slow flowing fresh water <2m deep: lakes, streams.
Seeds, rhizome fragments spread by water.
Mats block waterways, impeding drainage, disrupting recreational activities, choking hydro turbines. Out-competes native species.
Regular follow up required.
1. Hand clear small infestations.
2. Weedmat at least 3-4 months.
3. Spray emergent foliage, repeat as necessary (100ml glyphosate/10L, use glyphosate formulation approved for use over water).
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.