Plants of South Eastern New South Wales
Alternanthera philoxeroides
Common name
Alligator weed
Family
Amaranthaceae
Where found
Aquatic, moist places, and moist pastures. ACT. Sydney region and lower Blue Mountains north from Camden. Occasionally coastal north of Moruya.
Notes
Introduced perennial herb, prostrate or upright. Free-floating when aquatic. Stoloniferous, rooting at the nodes. Can form dense mats of vegetation up to 1 metre thick. Stems up to 10 m long, hairless. Leaves opposite each other, 2-14 cm long, 10-40 mm wide, margins entire, tips pointed. Flowers whitish, turning straw-coloured, with 5 papery 'petals', each 4-7 mm long, in almost globular to globular clusters of few to several flowers 8-20 mm in diameter. Flowers Spring to Autumn.
A Weed of National Significance. General Biosecurity Duty all NSW. General Biosecurity Duty with additional restrctions in Greater Sydney area. Pest plant ACT. Noxious weed Vic.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Alternanthera~philoxeroides (accessed 2 January, 2021)
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