Weed Seed: Blueweed/Viper's bugloss (Echium vulgare)

Family

Boraginaceae

Distribution in Canada

Found in Canada

Duration of life cycle

Biennial or short-lived perennial

Seed/Fruit type

  • nutlet - a one-seeded, dry fruit with a thick shell
  • nutlets develop in groups of 4

Seed identification features

Size

  • length: 2.5–3.0 mm
  • width: 1.25–1.5 mm

Shape

  • in outline: angular (diamond-shaped)
  • in cross-section: triangular

Surface texture

  • densely covered with small bumps
  • overlain with large, wart-like projections
  • overall surface is glossy

Colour

  • medium brown, dark brown between wart-like projections

Other structures

  • flat basal area is distinctive: dull, roughened and brown, with 2 peg-like projections and an open hilum

Similar species

Corn gromwell (Buglossoides arvensis)

  • found in BC, MB, ON, QC, NS, and across the United States
  • similar to blueweed in size, brown colour and triangular shape (corn gromwell nutlets are not as strongly angled)
  • rounded base

Gromwell (Lithospermum officinale)

  • found in MB, ON, QC, NB, and the northeastern United States
  • whitish colour
  • similar to blueweed in size and triangular shape (gromwell nutlets are more rounded)
  • rounded base

Photos

Photo - Blueweed (Echium vulgare) nutlet (inner side showing central ridge and basal hilum area)
Blueweed (Echium vulgare) nutlet (inner side showing central ridge and basal hilum area)
Photo - Blueweed (Echium vulgare) nutlet (outer side)
Blueweed (Echium vulgare) nutlet (outer side)
Photo - Blueweed (Echium vulgare) nutlets
Blueweed (Echium vulgare) nutlets

Similar species

Photo - Similar species: Corn gromwell (Buglossoides arvensis) (front view, showing ridge)
Similar species: Corn gromwell (Buglossoides arvensis) (front view, showing ridge)
Photo - Similar species: Gromwell (Lithospermum officinale) nutlet (side view)
Similar species: Gromwell (Lithospermum officinale) nutlet (side view)
Date modified: