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From
Hayley Anderson, Terrestrial Invasive Species Outreach Liaison,
Ontario Federation of Anglers and Hunters, Phone: (705) 748-6324
ext 243 If anyone wishes to report sightings of the following
or any other invasive species, they can contact the invading species
hotline at
1-800-563-7711 or report them online at www.invadingspecies.com
Dog-Strangling Vine: - Native to Europe (Ukraine) - Introduced
into the N.E. US in the 1880's and possibly introduced to Canada
from the Experimental Farms in Ottawa where it was being tested
for uses as lifejacket filler and possible rubber substitute during
WWII - Herbacious perennial - vines die every winter and will
stay twined around trees etc - Flowering begins late June and
flowers are dark purple - Seed pods produce fluffy white seeds
similar to native milkweed, which are carried by wind - Prefers
open sunny areas but will grow just about anywhere - especially
in filtered shade (pine plantations) - Forms dense colonies and
outcompetes/outshades native species - Spread is expected to increase
across North America & expand rapidly into new areas - Prevention
is the best control - always remove seeds, mud and plant parts
from yourself, your equipment and pets before moving to a new
area & try to limit your travels in DSV infested areas after
seeds have been released (late August) - Seeds can remain viable
in the soil for up to 5 years - so control must continue for several
years to be effective
Garlic Mustard: - Native to Europe - Introduced by in late
1800's by early settlers as food source/potherb green - Biennial
plant (first year as basal rosettes which survive over winter,
second year as flowering stalk which produces seed) - Grows up
to 1m in height with white flowers produced in May - Seed pods
can produce thousands of seeds per plant, and this is how it is
spread - Thrives in shade but can grow in a multitude of habitats
& wide variety of soils - Can enter and establish itself within
a stable, healthy forest site - so prevention measures (same as
DSV) should be taken to ensure it is not spread to new areas -
Roots contain Sinigrin, which interferes with the mychorrizal
(beneficial) fungi in the soil that aides tree growth - Also allelopathic,
emits chemicals which alter the soil chemistry and prevents native
plants from growing - Promising research shows GM may be out-competed
by pulling then planting native species (Bloodroot and Mayapple)
at 5-9 plants/sq m
European Buckthorn: - Native to Europe - Introduced in
1700's (for use as hedgerow/fencing) - Grow in large shrub growth
form with few to several stems - Drought and Shade tolerant and
can grow in a wide variety of sites (I've seen it growing under
complete shade in Cedar plantation) - Female trees produce berries
by late summer, which persist on the tree throughout winter -
berries have a laxative effect on the birds/animals that eat them
and this is how the plant is spread - Leaves are egg-shaped, with
veins that curve towards the centre, and there will often be a
small thorn between branches - May also be allelopathic - Seedlings
(when quite small) can be pulled by hand or by using weed wrench
- Control may be best started by identifying prolific seed producing
female trees first and removing them
Japanese Knotweed: - Native to Asia - Escaped ornamental,
planted in gardens and still available at some nurseries - Semi-woody
perennial, thick layers of stems and leaves produced will mulch
out any competitors - Looks similar to bamboo (but not related)
- hollow stems with swollen nodes - Leaves have a pointed tip
and flat base - Flowers are white and produced along the stems
- Requires sun & can often be found growing along riverbanks
and rail-beds - Shoots and roots can grow through concrete and
asphalt
Norway Maple: - Native to Europe, first introduced in the
1700's as an ornamental - Widely planted as a street tree after
Dutch Elm disease wiped out Elm trees in the 1930's and 40's because
it is tolerant of compacted soils and pollution - Still used quite
widely as a street tree, Crimson king is one of the cultivars
- Able to grow in deep shade - has infested ravines in Toronto
- seedlings form a thick mat and can choke out natural regeneration
of native tree species - Best control is to phase out its use
as a street tree and substitute native maples instead
Giant Hogweed: - Native to Asia - Escaped ornamental, becoming
more common in southern Ontario
- Very LARGE member of the parsley family - grows up to 5 m (16ft)
in height - Stem is bristly, hollow, and green with purple splotches
- Flower umbels and leaves can be up to 1 m across - white flowers
similar to our native species Cow Parsnip or Angelica but much,
much larger - HEALTH HAZARD - the clear, watery sap of giant hogweed
contains toxins that cause photodermatitis (increase our skins
sensitivity to sunlight) skin contact with the sap followed by
exposure to sunlight can result in painful burns and blisters
