Hygrophila

• Erect, emergent herb up to about 1m tall.
• Leaves opposite, simple, 3–18cm long, 1–5cm wide, oblong to elliptic, coarse in texture, with prominent veins and distinct midrib.
• Papery, white flowers, 9–11mm wide, produced in clusters where leaf joins stem.
• Spreading stems sprout new roots from nodes where they contact soil.
• Larger stems can be quite robust.
• Fruit is a 2-valved capsule, 14–17mm long.
• Each capsule has 12–18 seeds.
• Seeds are pale brown, round, flattened, smooth, 0.3–1mm long.

• Found along creekbanks and in shallow, freshwater wetlands.

• Visit the Weeds Australia website and click on the distribution tab to access the distribution map.

• Flowering and fruit production occurs from December–March.

Environmental

• Grows aggressively and competes with native water plants.
• Forms mats of dense, floating growth at the edges of freshwater lakes.

• Can spread by floodwaters.

• Find out how farmers can prevent weed spread.
• Find out how gardeners and outdoor enthusiasts can prevent weed spread.

Herbicide control

• Permit no. PER11567 allows the use of glyphosate for hygrophila control in aquatic and semi-aquatic situations. Visit the Australian Pesticides and Veterinary Medicines Authority for more information.

• Hygrophila is a category 3 restricted invasive plant under the Biosecurity Act 2014.
• You must not give away, sell, or release into the environment. Penalties may apply.
• You must take all reasonable and practical measures to minimise the biosecurity risks associated with dealing with hygrophila under your control. This is called a general biosecurity obligation (GBO).
• At a local level, each local government agency must have a biosecurity plan that covers invasive plants in its area. This plan may include actions to be taken on hygrophila. Some of these actions may be required under local laws. Contact your local council for more information.