|Water Pepper photos|
|Scientific Name:||Persicaria hydropiper (syn. Polygonum hydropiper)|
Water Pepper plants
Photo: A J Brown
Other Common Name:
Cosmopolitan plant which may or may not be native to Australia.
Erect to ascending, hairless, annual herb from 50-120 cm high with narrow-ovate leaves, 5-12 cm long and 10-25 mm wide. Has a hot peppery taste.
Flowers in elongate-cylindrical, slender clusters, 3-9 mm long and often drooping. Perianth (flower) segments, white, 2.3-3.8 mm long. Fruit a lens-shaped nut, 2-2.2 mm long and dark brown to black.
Semi-aquatic plant of freshwater environments. Grows in water and on wet flats at the edges of rivers, lagoons and lakes and in marshes, swamps and drainage lines. High waterlogging tolerance. Not tolerant of shade.
Water-pepper belongs to a group of about 10 species which were once treated as part of the genus Polygonum. The four species left in Polygonum are mainly introduced plants which frequent waste ground or weeds of cropping ground and are not associated with waterlogged situations. Other Knotweeds of wide distribution, include the Australian native Spotted Knotweed (Persicaria praetermissa), Creeping Knotweed (Persicaria prostrata), Slender Knotweed (Persicaria decipiens) and Pale Knotweed (Persicaria lapathifolia). The introduced Persicaria or Redshank (P. maculosa) is a common weed of waterbodies in Gippsland. Its flower-spikes and shorter and broader than in Slender Knotweed