Weed Seed: Wild buckwheat (Fallopia convolvulus)

Family

Polygonaceae

Synonyms

Polygonum convolvulus

Distribution in Canada

Found in Canada

Duration of life cycle

Annual

Seed/Fruit type

  • achene - a one-seeded, dry fruit
  • often partially or totally enclosed in a papery covering derived from the flower

Seed identification features

Size

  • length: 2.5–3.5 mm
  • width: 2.0–2.5 mm

Shape

  • in outline: oval (widest at middle)
  • in cross-section: strongly triangular

Surface texture

  • on achene faces: roughened with fine lines
  • on edges: smooth and shiny

Colour

  • mature achenes: black
  • immature achenes: dull brown

Other structures

  • outer covering may wholly or partially cover the achene
  • outer covering is light brown, slightly wrinkled and papery, with lines where lobes overlap

Similar species

Prostrate knotweed (Polygonum aviculare)

  • found across Canada and the United States
  • similar to wild buckwheat in size (prostrate knotweed is slightly smaller in width by 0.5 mm), black colour, triangular cross-section, widespread distribution and roughened surface texture
  • seeds do not have smooth edges
  • obovate (egg-shaped) outline, with widest point below middle

Photos

Photo - Wild buckwheat (Fallopia convolvulus) achene covered by papery covering
Wild buckwheat (Fallopia convolvulus) achene covered by papery covering
Photo - Wild buckwheat (Fallopia convolvulus) achene without papery covering
Wild buckwheat (Fallopia convolvulus) achene without papery covering
Photo - Wild buckwheat (Fallopia convolvulus) single seed found within achene (fruit)
Wild buckwheat (Fallopia convolvulus) single seed found within achene (fruit)
Photo - Wild buckwheat (Fallopia convolvulus) group of achenes and a single seed
Wild buckwheat (Fallopia convolvulus) group of achenes and a single seed

Similar species

Photo - Similar species: Prostrate knotweed (Polygonum aviculare) achenes
Similar species: Prostrate knotweed (Polygonum aviculare) achenes
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