Common name: Chinese knotweed
Persicaria chinensis (L.) H.Gross APNI*
Synonyms: Polygonum chinense L. APNI*
Description: Rhizomatous perennial, stems ascending to erect to 1 m, sometimes climbing.
Leaf blade ovate or elliptic, 4–15 cm long, 2–8 cm wide, yellow-green, often with a central darker green V-shaped blotch (with a pale margin) towards the base, glabrous; petiole 1–2.5 cm long; ocreas without cilia.
Inflorescences paniculate, open, with 1–3 flowers per distant cluster; branches glandular-hairy; perianth segments 3–4 mm long, white or pale pink.
Achene trigonous, 2.8–4 mm long, 2–3 mm diam., black, enclosed by enlarged succulent, blue-black persistent perianth.
Distribution and occurrence: Occasionally cultivated as an ornamental; naturalised on a roadside in Glenrock State Conservation Area, Newcastle, and on swamp margins in Rockdale, Sydney. Weedy (potentially a major weed) in coastal NSW and Qld since it is strongly rhizomatous. Native of Asia and SE Asia; widely cultivated and naturalised in other parts of the world.
NSW subdivisions: *NC, *CC
Leaves of this species are described as usually being auriculate (having two small green lobes at the base of the pedicel). The leaves of Glenrock plants seen to date are not auriculate, but illustrations from various regions of the world also show non-auriculate leaves.
Text by KL Wilson (2012) based on Hinds and Freeman (2005); edited KL Wilson (March 2014)
Taxon concept: HR Hinds and CC Freeman (2005) Fl North America vol 5
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.