Hazardous plants

Poison ivy can often be found growing along the edges of park trails. Touching the plant transfers an oily resin called urushiol to your skin, which causes an itchy rash or blisters. Poison ivy can be identified by its clusters of three leaves, with the middle leaf having a longer stem than the two side leaves. Poison ivy can grow in short patches close to the ground or as a vine that climbs up trees, shrubs, and posts. The plant appears reddish in the spring, green in the summer, and red, orange, or yellow in the fall. You can avoid contact with poison ivy by staying on trail and keeping your dog on a leash to reduce the chance of the resin transferring from your pet's fur to your skin.

The sap of this plant contains a phototoxin which reacts with UV radiation. It can cause a rash if it gets onto your skin when you are out in the sun. Cow parsnip grows to 1 to 3 metres in height and has clusters of small white flowers, thick stems, and large compound leaves.

Spotted water hemlock is present throughout North America and can usually be found growing near water. The plant has tiny white clusters of umbrella-shaped flowers that bloom between June and August and reaches an average height of between one and two metres. If you find spotted water hemlock in Rouge National Urban Park, please email rouge@pc.gc.ca or call 416-264-2020 and be prepared to share the plant's location and GPS details.