Poisonous Hemlock (Conium maculatum) is an extremely poisonous plant. There is great concern over this plant due to the personal safety of humans, foraging domestic animals and wild life. Most of the cases of poisoning to humans has been the result of foragers misidentifying the plant, believing the root to be that of the edible cow parsnip, or the leaves that of wild celery. Although … Continue reading Poisonous Hemlock (Conium maculatum)
Poison Sumac (Toxicodendron vernix) is a perennial shrub or small tree, native to eastern Canada as well as east-central and eastern United States. Like poison ivy and poison oak the leaves and berries of this plant contain urushiol (an oily mixture of organic chemical compounds); but the oil is said to be more concentrated in poison sumac. The Urushiol can cause a severe allergic reaction in sensitive … Continue reading Poisonous to Touch Weed Series: Poison Sumac (Toxicodendron vernix)
Wild parsnip (Pastinaca sativa) aka poisonous parsnip is one of the phototoxic weeds we grow here in Canada. It is a non-native and as such is an aggressive and invasive species. It is the only one of the phototoxic weeds that has a yellow flower, the others bearing white umbels. It’s pinnately compound leaves are also quite different than the palmately compound leaves of cow … Continue reading Poisonous to Touch Weed Series: Wild Parsnip (Pastinaca sativa)
Giant hogweed (Heracleum mantegazzianum) is likely the largest and most dangerous to touch perennial weed in North America. In Ontario it commonly reaches heights of 3-4.5m but in other parts of the world it can reach heights of 5.5m (MacDonald F. and Anderson H. 2012). There are a few other Giant Hogweed species that are a bit smaller in size but Heracleum mantegazzianum is the … Continue reading Poisonous to Touch Weed Series: Giant Hogweed (Heracleum mantegazzianum)
By: Kimberley Pacholko Eastern Poison Ivy, (Toxicodendron radicans) and Western Poison Ivy (Toxicodendron Rydbergii ) are important plants to learn how to identify for personal safety. Touching any part of this plant can cause a painful itchy rash with red swollen skin and painful blisters. I have had the miss fortune of being caught twice by this plant and can testify to how unpleasant the … Continue reading Poisonous to Touch Weed Series: Poison Ivy (Toxicodendron radicans and Toxicodendron Rydbergii)
Horticulture For Home Gardeners 