Citation: Brouss. ex Willd., Enum. Hort. Berol. 1:428 (1809)

Synonymy: P. decipiens R. Br., Prod. Fl. Nov. Holl. 419 (1810); P. serrulatum Lagasca, Gen. Sp. Pl. 14 (1816); P. minus sensu J. Black, Fl. S. Aust. 283 (1948), non Hudson (1762).

Common name: Slender knotweed.

Description:
Almost glabrous annual or perennial; stems slender, prostrate, ascending or erect, to c. 1 m long; leaves lanceolate, almost sessile, 5-10 x 0.5-2 cm, sometimes hairy below; stipular sheaths with long cilia.

Flowers reddish, in loose slender pedunculate 3-5 cm long spikes which are sometimes twin and forming a terminal panicle, the bracts ciliate; stamens 5 or 6; styles 2 or 3.

Nut black, shining, 2-2.5 mm long, trigonous or biconvex.

Published illustration: Rotherham et al. (1975) Flowers and plants of New South Wales and southern Queensland, fig. 547.

Distribution:    All mainland States. Conservation status: naturalised Flowering time: throughout the year.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: Many authors have treated this as an introduced species from Europe and Asia. It is, however, quite possible that it is native, as several recent authors have claimed. If it is native, its correct name would be P. decipiens.

Author: Not yet available