Polygonum persicaria

Scientific Name Polygonum persicaria (L.)Small
Synonyms Periscaria maculosa Gray
Common Names English: Spotted ladysthumb, redshank; German: Floh-Knöterich; French: Renouée persicaire; Spanish: Persicaria, Duraznillo
Description Annual, seed-propagated weed with ramified taproot.

Descriptions

Characteristic Features

Ocrea with small hairs emerging from the upper end.
Characteristic purple splotch in the center of the leaf. The spot is not always present but typical.
The perianth is somewhat variable in color.

Cotyledons

Long-oval, rounded tip, dark green to reddish.

Stems

Similar to Pale persicaria (Persicaria lapathifolium), up to 80 cm (31.49 inch) high.

Leaves

Lanceolate, widest in the middle, upper surface often with dark spots, short-petiolate or sessile.
Membranous tubes at the leaves' base often with short, appressed hairs.
Visibly ciliate at the margin.

Propagatio Organs

Flowers

Small, pink or whitish; in erect, dense, terminal or axillary, spiciform inflorescences.
Perianth parts glabrous, ovate to orbicular.

Flowering Period

Midsummer - autumn.

Fruit

Achenes typically 2-sided, black, shiny, to +/-2mm (0.078 inch) long.

Seeds

Germination from spring - summer.
Seed germination depth usually 1-3 cm (0.39 - 1.18 inch).
Seeds are lentiform and shiny black.

Viability Of Seeds

30 years.

Propagation

By seeds.
200-800 seeds/plant.

Occurrence

Habitat

Moist to wet waste ground, disturbed sites, meadows, streambanks, roadsides, railroads.

Soil

Fertile, nitrogen-rich, friable, well-aerated soils.

Agricultural Importance

P. persicaria is a serious agricultural weed in many temperate regions. It greatly reduces yield and interferes with combine harvesting. Seed production is stimulated by wet conditions.

Control

Integrated Crop Management

A combination of preventive, physical and chemical control methods may reduce P. persicaria development.

Chemical Control

It is important to rotate modes of actions in order to avoid resistant weed populations.

Choose directly from Category

Pests

Pests

Search directly for a particular pest

Diseases

Diseases

Search directly for a particular disease

Weeds

Weeds

Search directly for a particular weed

Choose by Crop