Weed Seed: Common hemp-nettle (Galeopsis tetrahit)
Family
Lamiaceae
Distribution in Canada
Found in Canada
Duration of life cycle
Annual
Seed/Fruit type
- nutlet - a 1-seeded dry fruit with thick shell
- develop in groups of 4 nutlets
Seed identification features
Size
- length: 2.5–3.0 mm
- width: 2.0–2.5 mm
Shape
- in outline: obovate (upside-down egg-shaped), with widest point above middle
- in cross-section: lens-shaped
Surface texture
- bubbled with random pattern
- slight sheen overall
Colour
- medium brown
- bubbled areas are light brown, with occasional black spots
Other structures
- hilum area is at base of seed (cut diagonally)
- hilum area is dull and roughened
Similar species
Good reference material is needed to distinguish these 3 species.
Hairy hemp-nettle (Galeopsis pubescens)
- native to Europe; not yet found in North America
- similar to Common hemp-nettle in size, obovate shape, single diagonal hilum, and bubbled surface pattern with black spots
- darker brown and oval shaped (not as narrowed at hilum end as Common hemp nettle)
Large-flowered hemp-nettle (Galeopsis speciosa)
- found in AB, ON, QC
- similar to Common hemp-nettle in size, obovate shape, single diagonal hilum, and bubbled surface pattern with black spots
- darker brown colour than Common hemp-nettle
- hilum end more strongly narrowed than Common hemp-nettle
Photos
Similar species
- Date modified: