Plants of South Eastern New South Wales

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Persicaria elatior

Common name

Tall knotweed



Where found

Swampy forest, disturbed sites, moist places, and stream banks. Coast, occasionally in the ranges.


Herb to 1.2 m high. Stalked gland-topped hairs present on most parts, occasionally glands without stalks present too. Leaves alternating up the stems, 3–11 cm long, 10–30 mm wide, sticky. Flowers with 4-5 pink 'petals' each 3.0–3.8 mm long. Flower spikes cylindrical, dense, 1.8–5 cm long, 5–7 mm diameter.

Vulnerable Australia. Vulnerable NSW. Provisions of the Biodiversity Conservation Act 2016 No 63 relating to the protection of protected plants generally also apply to plants that are a threatened species.

NSW Threatened Species profile: (accessed 29 January, 2019)

PlantNET description: 29 January, 2019)