Family
Asteraceae
Synonyms
Matricaria maritima
Distribution in Canada
Found in ON, QC, NB, NS, NL
Duration of life cycle
Perennial (occasionally biennial)
Seed/Fruit type
Achene - a one-seeded, dry fruit
Seed identification features
Size
- length: 2.0–3.5 mm
- width: 1.0–1.5 mm
Shape
- in outline: rectangular
- in cross-section: square
- three ribs evident on one side (no ribs on the other side)
Surface texture
- smooth on ribs, bumpy between ribs
- ribs tend to be close together
- overall sheen
Colour
- ribs are medium brown (occasionally light)
- dark brown between ribs
Other structures
- achene has 2 ends
- top has a small peg surrounded by a jagged rim
- bottom has a small ring
- 2 depressions occasionally appear at the top of the achene on the non-rib side (dark brown or red, usually oval-shaped)
Similar species
Scentless chamomile (Tripleurospermum maritimum subsp. inodorum)
- found across Canada and the northern United States
- similar to false mayweed in size (scentless chamomile tends to be ~0.5 mm smaller), rectangular shape, colour, markings and the presence of ribs (it is difficult to distinguish from false mayweed with accuracy)
- tends to have wider spaces between ribs
- 2 dots on the non-rib side are round
Photos
Similar species
