Persicaria decipiens, commonly known as slender knotweed, is a species of flowering plant native to Australia and Asia.

[2] Persicaria decipiens is a trailing plant whose stems grow horizontally at first but become more vertical with time,[3] reaching 30 cm (1 ft) high.

[3] Persicaria decipiens was among the plants collected by Joseph Banks and Daniel Solander on 5 May 1770 at Botany Bay during the first voyage of Captain James Cook.

[4] Prolific Scottish botanist Robert Brown described the species as Polygonum decipiens in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen.

It is found across Africa and the Mediterranean,[6] through southwestern Asia, Malesia and all states of Australia, as well as Norfolk Island, New Zealand and New Caledonia.