Family
Boraginaceae
Synonyms
Lithospermum arvense
Distribution in Canada
Found in BC, MB, ON, QC, NS
Duration of life cycle
Annual
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: 1.5 mm
Shape
- in outline: egg-shaped
- in cross-section: rounded triangular
Surface texture
- shiny with scattered warts and pits
- raised ridge on inner side
Colour
- grey to grey-brown
- brown base and surface pits
Other structures
- rounded base is a distinguishing feature
- base is dull, brown, with 2 raised warts
Similar species
Blueweed (Echium vulgare)
- found across Canada and the United States
- similar to corn gromwell in size, triangular shape and brown colour
- strongly angled nutlets, with raised rim around base
Gromwell (Lithospermum officinale)
- found in MB, ON, QC, NB, and the north-eastern United States
- similar to corn gromwell in size, shape, and rounded, brown base
- nutlets are more rounded and a whitish colour
Photos
Similar species
