Species

Persicaria strigosa

Etymology

Persicaria: Medieval name referring to the likeness of the leaves to a peach tree

Authority

Persicaria strigosa (R.Br.) H. Gross

Family

Polygonaceae

Brief Description

Prickly scrambling herb, either forming dense patches or scrambling through other vegetation, leaves mostly triangular in outline with backward pointing lobes, small (2 to 3 mm long) pink flowers in open branched flowerheads at the top of stem.

Flora Category

Vascular - Exotic

NVS Species Code

POLSTR

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Polygonum strigosum R.Br.

Distribution

Northland to northern Waikato.

Habitat

Swamp and water body margins.

Features

Annual herb; stems to > 50 cm long, lax or sprawling, with numerous deflexed scabrid bristles to c. 1 mm long; roots slender. Lvs ± similar; petiole to 1 cm long, filiform, scabrid. Lamina 3-7 × 0.5-1.2 cm, linear-lanceolate; midrib below with scattered bristles; margin ciliolate, entire; base ± hastate or sagittate; apex obtuse or subacute. Ochreae usually 1-1.5 cm long, glabrous, soon brown and papery; apex truncate. Racemes terminal or in axils of upper lvs, to 12 cm long, very slender; fls few, distant. Peduncles dichotomous, conspicuously glandular-hairy, > lvs; pedicels very short, hidden by sheathing, glabrous or glabrate bracts until after anthesis. Perianth 2-3 mm long, accrescent, pink; segments ± broadly ovate-elliptic, imbricate and remaining almost closed, eglandular. Nut 2-2.5 mm long (including short beak), broad-ovoid or ellipsoid, brown, shining.

Similar Taxa

Unlike any other willow weed, with prickly stems and leaves and the sprawling growth habit.

Flowering

January to February

Flower Colours

Red / Pink,White

Fruiting

Autumn

Year Naturalised

1976

Origin

Eastern Australia

Reason for Introduction

Unknown, seed or soil contaminant.

Control Techniques

Not controlled in New Zealand.

Life Cycle and Dispersal

Seed dispersed by water, animals or contaminated machinery.

Attribution

Prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al. (1988).

References and further reading

Johnson PN, Brooke PA (1989).  Wetland plants in New Zealand.   DSIR Field Guide, DSIR Publishing, Wellington. 319pp.

Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.

This page last updated on 21 Aug 2013