Persicaria strigosa (POLYGONACEAE) Spotted Knotweed

Plants to Plant

Herb with stems creeping, prostrate to decumbent, slender, common in open swamps and still sections of creeks. Leaves to 6.5 cm long (hasteate), 15-32 mm wide, petiole 8-25 mm long. Inflorescence of 2-4 branches with small terminal subglobose flower clusters 5-10 mm long with bracts crowded at end of branches. Perianth segments 3.0-3.7 mm long, pink or white. Fruit is a dark red-brown lenticular or trigonous nut to 3 mm long.

Photo: Robert Whyte

Foliage and Flowers

Persicaria strigosa comes from Australia and has become naturalised in some other places in the world, including New Zealand. It may be a weed in some parts of Australia.

Photo: Robert Whyte

Flowers Close-up

Listed as a frog friendly plant by Wolli Creek Preservation Society: “Common dense groundcover herb, with striking, white, flowerheads. Found in marshes and beside creeks, suits moist or submerged position, in sun or semi-shade, suitable for bog and pond, provides good cover for frogs such as Striped Marsh Frogs and Peron’s Tree Frogs, likely to attract seed-eating birds.” 
Photo: Robert Whyte