Taking a walk along highway 6, roads west of highway 6 through the Eastnor Flats or even in Stokes Bay can be dangerous – and it’s not because the tourists making U-turns to reach the chip truck in Ferndale! In the past 2 or 3 years an invasive species of plant called Pastinaca Sativa or “wild parsnip” which made it’s way from Asia and Europe, has become common place in the Bruce Peninsula. The plant was brought to North America by European settlers who grew it for its edible root. It is related to cow parsnip, water hemlock, water-parsnip, as well as giant hogweed. Interestingly, wild parsnip is also related to Queen Anne’s lace from which our familiar carrot was derived.
What looks like a colourful wildflower is actually a toxic plant that could burn your skin and hurt your eyes. It grows in large patches or as scattered plants along roadsides, public recreation areas, around sports fields, pastures, fence rows and in disturbed open areas. It can grow as tall as two metres.
The problem with this plant is that it’s sap from broken stems and leaves contains a chemical compound called psoralens (more precisely, furocoumarins). This compound is very toxic to fish, and some compounds actually are intentionally deposited in streams in Indonesia to catch fish. Once these furocoumarins are absorbed by the skin, they are energized by UV light on both sunny and cloudy days. They then bind to our DNA and cell membranes, destroying the cells and skin. So, it’s not an allergic reaction like there is from contact with poison ivy, but rather, more like a chemical burn. Within 24 to 48 hours, the affected area will first redden and in most cases be followed by blisters that can be painful for a couple of days. In many cases, the blisters will lead to brownish pigmentation that can last for years.
Here is what that burn can look like – initially and then a sever case 4 days later.
People who come in contact with the toxic liquid are advised to quickly seek shelter to stop the sap from photosynthesizing, and to wash exposed skin thoroughly with soap and water. Skin can turn red one day after exposure. Inflammation may also occur after three days. Those who have a reaction are advised to seek medical attention. If the sap gets into the eyes, it may even cause temporary or permanent blindness.
What about my pets? The plant has a chemical in the leaves that is secreted in the plant oil which could find it’s way on pets feet if they walk through the plants, or likely on a cat’s tongue after grooming,” explains Dr. Jeff Latimer of Princess Animal Hospital. “Because most dogs and cats are not attracted to the plant, I feel that seeing these lesions are unlikely as the pet would have to find the plant, walk through it, then get enough sun light to cause the reaction.
How To Recognize It
The plant is pretty easy to identify. It’s a Biennial plant, the first year it shows up as a low spindly rosette of leaves. The leaves come in from 5 to 15 pairs of leaves that are heavily toothed. Here is a young plant in it’s first year:
In the second year it can grow as high as 1.5 to 2 metres, and has an umbel shaped flat headed set of yellow flowers. Also note the heavily ridged stem.
and a closeup of the leaves:
Pictures above courtesy of Weedinfo
How to Get Rid of It
The simplest method of control may be to regularly cut the grass/plants/weeds in green areas alongside roads, and in areas the public uses. This may prevent the spread of wild parsnip into new areas. If you only have a few of them in your yard, you can remove them by digging or hand pulling (especially after some extended wet weather. Be sure to wear shoes or boots, long pants, long sleeves, gloves and goggles when you are working near it. Dispose of the plants in the garbage. To do otherwise will spread them further.
For large infestations, mowing at the right time of the year can help to control them. Mow or “weed eat” it just when the flower buds are beginning to show (somewhere between end of June and beginning of July). It’s crucial to remember that cutting the plant down with a mower or trimmer later in the season is not a good idea because mowing leads to re-sprouts and weed whacking spreads the toxic sap.