- Taxon
- Weed
- Gallery
Recognition
- an aquatic plant, either forming a rounded bush or a tangled mass of vegetation along waterways.
- its stems (up to 20 mm thick) are hollow between the joints and its leaves are arranged in opposite pairs.
- these leaves are somewhat elongated in shape (4-20 cm long and 1.5-8 cm wide) and have toothed margins.
- its flower-heads are fluffy in appearance (12-20 mm across), white or pale purplish-white in colour, and arranged in small dense clusters at the tips of the leafy branches.
- its yellowish-brown 'seeds' (about 5 mm long) are ribbed and hairless.
References
Biosecurity New Zealand 2012: Regional Pest Management Strategies Database. http://www.biosecurityperformance.maf.govt.nz/
Biosecurity New Zealand 2008: National Plant Pest Accord. MAF Biosecurity New Zealand, Wellington.
Howell, C. 2008: Consolidated list of environmental weeds in New Zealand. DOC Research & Development Series 292: 42.
Ministry for Primary Industries 23 Feb 2017: Unwanted Organisms Register. Version 02.01.02. https://www1.maf.govt.nz/uor