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Persicaria lapathifolia

Species category

Weed

Common name

curlytop knotweed

Diagnostic characters

Planting unit

AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.

Shape

Compressed ovateOvate:
Egg-shaped with basal end the broadest.

Size

  • Length 2–2.2 mm 
  • Width 1.7–2 mm 
  • Thickness 0.5–0.6 mm 

Color

Reddish-brown

Texture

Rough 

Other structures

Remnants of floral parts may be present. Shrunken area present in the center of the sides.

Identification notes

AcheneAchene:
A dry, hard, one-chambered, one-seeded indehiscent fruit, as in buckwheat (Fagopyrum) or sunflower (Helianthus). The fruit wall is not united with the seed coat.
 is two-sided with a shrunken area in the center of each side. Shape would be orbicular except for the acute point at the apexApical:
The distal end of the fruit or seed away from the point of attachment or attachment scar.
.

Noxious weed seed categories

Not listed

AOSA examination list

Included

Nomenclature

Family

Polygonaceae

Valid name

Persicaria lapathifolia (L.) Gray

Synonyms

Persicaria incarnata (Elliott) Small
Persicaria tomentosa (Schrank) E.P. Bicknell
Polygonum incarnatum Elliott
Polygonum incanum F.W. Schmidt
Polygonum lapathifolia L.
Polygonum lapathifolium L. var. incanum (F.W. Schmidt) W.D.J. Koch 
Polygonum lapathifolium L. var. nodosum (Pers.) Small
Polygonum lapathifolium L. var. ovatum A. Braun
Polygonum lapathifolium L. ssp. pallidum (With.) Fr.
Polygonum lapathifolium L. var. prostratum Wimm.
Polygonum lapathifolium L. var. salicifolium Sibth.
Polygonum nodosum Pers.
Polygonum oneillii Brenckle
Polygonum pensylvanicum L. ssp. oneillii (Brenckle) Hultén
Polygonum scabrum Moench
Polygonum tomentosum Schrank

Polygonum lapathifolia. Reddish-brown achenes with a shrunken area in the center of each side. 
Polygonum lapathifolia. Reddish-brown achenes with a shrunken area in the center of each side.