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. glandular hairs present on most parts, occasionally glands without stalks present too. Leaves alternating up the stems, 3–11 cm long, 10–30 mm wide, with stalkless glands and scattered stalked glandular hairs on both surfaces, margins hairy, stipular sheath (ocrea) with glandular hairs about 0.5 mm long on the upper margin. 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 in 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 7 January, 2021)

PlantNET description: 7 January, 2021)