Spotted ladysthumb (Polygonum persicaria)

Synonyms: Persicaria maculata, Persicaria maculosa, Persicaria persicaria, Persicaria puritanorum, Persicaria ruderalis, Persicaria ruderalis var. vulgaris, Persicaria vulgaris, Polygonum dubium, Polygonum fusiforme, Polygonum minus, Polygonum minus var. subcontinuum, Polygonum persicaria var. angustifolium, Polygonum persicaria var. ruderale, Polygonum puritanorum

Common Names: Lady's thumb, ladysthumb smartweed, smartweed, redshank, Jesusplant

Description: Contains a chemical which can burn.

Habit:

Leaves: Alternate, lanceolate to elliptic, 3-15 cm long and 0.5-3 cm wide, typically found with dark green or purple splotch, often v-shaped.

Stems: Smooth, erect, branching, swollen nodes that appear reddish, ocrea at nodes, short stiff hairs on top margin of ocrea.

Flowers: Bright pink to purple sometimes white in color, petals absent, clusters form a short terminal spike.

Fruit and seeds: Black in color, shiny, two-sided, lenticular achene that reaches a size of 2-2.5 mm long.

Habitat: Native to Europe and China. Can be found in wet areas of waste grounds, meadows, river banks, roadsides, railroads and disturbed sites. Also near springs, shores, stream banks and irrigation ditches.

Reproduction: By seed or vegetatively.

Similar species: Pennsylvania smartweed (Polygonum pensylvanicum), curlytop knotweed (Polygonum lapathifolium)

Monitoring and rapid response: Tilling is effective as well as hoeing (in home gardens) and repeated mowing, which prevents seed production. Capable of becoming resistant to certain herbicides.

Credits: The information provided in this factsheet was gathered from CABI: Invasive Species Compendium and the Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS).

Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org). Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).

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