HomeMy WebLinkAboutScentless Chamomile.pdf Cluster (R. Mueller) Flower head Leaf
Maple Ridge Noxious Weeds Program
Scentless Chamomile
(Matricaria perforate or Matricaria maritima)
Designation: Provincially Noxious
Photo: L. Scott
History:
Scentless Chamomile was introduced to Canada
in the 1930’s from Europe. The plant is believed
to have been transferred as an ornamental or
contaminate of crop seed.
How to Identify:
Size: Mature plants are 5 – 100 cm tall.
Flowers: Single, white, daisy‐like flowers with
yellow centers at the ends of each branched
stem. Flowers are 2 – 3 cm in diameter and
odourless (scentless) when crushed. Flowers
from June to October.
Leaves: Basal leaves disappear by flowering time.
The stem leaves are alternate, usually smooth,
and finely divided into short, thread‐like
segments. Leaves are odourless when crushed.
Stem: Stems are erect to semi‐erect, smooth,
and branched. Mature plant tends to be bushy
when not subjected to competition.
Location: Grows from low‐ to mid‐elevations in
BC and is found on dry shorelines, roadsides,
fence lines, disturbed areas, and perennial
forage crops. Prefers areas with high soil
moisture and is commonly found near ponds,
streams, and other areas prone to seasonal
flooding.
Mistaken Identity: Several introduced (non‐
native) plants have flowers and leaves similar to
scentless chamomile. Leaves of wild chamomile
(Matricaria recutita), stinking mayweed
(Anthemis cotula), and pineapple weed
(Matricaria discoidea) have a strong odour when
crushed, while scentless chamomile leaves are
almost odourless. Oxeye daisy (Leucanthemum
vulgare) has similar flowers, but the leaves on
scentless chamomile are much more finely
dissected.
Danger / Impact
Economic: Can reduce crop and pasture yield
and is unpalatable to livestock.
Ecological: Primary impacts are to aquatic
systems where monocultures form near
waterbodies or riparian areas, on sites with
heavy soils and high soil moisture, or in areas
that are subjected to periodic flooding.
Management:
Prevention:
• Monitor for scentless chamomile on both disturbed
and undisturbed sites.
• Look for seed mixtures that indicate where the
seed material was collected, request only non‐
invasive species, and know the level of
‘contamination’ from your seed supplier.
• Ensure soil, gravel, and other fill material are not
contaminated.
• Avoid unloading, parking, or storing equipment and
vehicles in infested areas.
• Minimize soil disturbance during activities and re‐
vegetate exposed soil as soon as possible.
• Remove plants, plant parts, and seeds from
personal gear, clothing, pets, vehicles, and
equipment. Wash vehicles, including tires and
undercarriage, and equipment at designated
cleaning sites before leaving infested areas.
• Take special care when controlling scentless
chamomile near streams or ditch lines to prevent
the movement of plant parts downstream.
• Maintain or establish healthy plant communities
that are resistant to invasion by invasive plants.
Mechanical Control:
Mowing can be used to reduce seed production and
should be done early and often before flowers are
formed. Each successive mowing should be lower
than the previous one, as plants will form new
flowers in the leaf axils below mowing height.
• Hand pulling small infestations before they go to
seed can prevent new infestations from
developing.
Chemical Control:
If applied correctly, herbicide applications are most
effective early in the season before flowering, but
can be done throughout the season as long as plants
are green and actively growing.
Disposal: Bury or dispose of plant material in a
landfill. Bag or tarp plants, plant parts, and seeds
before transporting to a designated disposal site (e.g.
landfill).
Follow‐up: Monitor controlled infestations
throughout growing season.
Restoration and Planting Alternatives:
Scentless chamomile does not compete well with
vigorous plants.
Photo: Ministry of Agriculture and Lands
Distribution in DMR:
Extensive but low density.
Who Do you Call?
1) REPORT PROHIBITED WEEDS – Report‐A‐Weed: www.reportaweedbc.ca 1‐888‐WEEDSBC
2) DMR: 604‐467‐7363 – AND SEE: http://www.mapleridge.ca/714/Invasive‐Plant‐Species
Information and photos:
http://www.bcinvasives.ca/images/stories/documents/tips/Chamomile_TIPS.pdf
http://www.agf.gov.bc.ca/weedsbc/pdf/scentless_chamomile.pdf
http://iscmv.ca/target‐species/species‐profiles