Plants of South Eastern New South Wales
Persicaria lapathifolia
Common name
Pale knotweed
Family
Polygonaceae
Where found
Moist disturbed sites, along streams, roadside ditches, and in water. Widespread. Mostly Sydney area and the ACT.
Notes
Annual or biennial herb to 1.8 m tall. Stems hairless, often reddish, occasionally densely hairy, often slightly sticky. Leaves alternating up the stems, 6-21 cm long, 8-60 mm wide, hairless to hairy, with glands dense on the lower surface and scattered on the upper surface, midrib and margins hairy or rough, stipular sheath (ocrea) without fringing hairs. Flowers pink, sometimes pale or greenish, with 4-5 'petals' each 1.5-3 mm long, in dense oval to cylindrical spikes 20-80 mm long, often several together. Flowers Sep.–May.
Regarded as native in NSW and ACT, and of Uncertain Status (native or naturalised) in Vic.
All native plants on unleased land in the ACT are protected.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Persicaria~lapathifolia (accessed 13 April 2021)
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