The previous posts have information that may be interesting, but is not exactly critical stuff to know. This post attempts to correct that by providing info that is at least somewhat useful.
A Highly Noxious Plant
Western Poison Ivy (Toxicodendron rydbergii)
Poison Ivy is recognized by groupings of three oval pointed leaves, its woody stems, and small green berries that persist throughout winter.
Its sap contains the toxin 3-n-pentadecyl-catechol, aka urushiol, which is found throughout the plant. This poison oozes from poison ivy when it is bruised or broken, and remains toxic indefinitely. Sensitivity to poison ivy varies among people, but very few are totally immune. Particularly insidious is inhalation of smoke from burning poison ivy, which can cause severe allergic reaction.
Our dogs sometimes walk through poison ivy along the roadside with no problems. This is not unexpected, apparently only humans are susceptible. Several animals actually eat poison ivy berries without ill effects.
Under the Minnesota Noxious Weed Law, landowners can be forced to eradicate colonies of poison ivy
Wolves in sheep’s clothing
Orange Hawkweed (Hieracium aurantiacum) and Hoary Alyssum (Berteroa incana)
These flowers are attractive, but are actually quite undesirable.
We noticed orange hawkweed (aka Fox-and-Cubs) along the Heartland bike trail near Akeley MN. Initial enthusiasm about finding something new evaporated upon learning that it is a highly invasive non-native species. Originally it is from Northern and Central Europe, first coming to North America in Vermont as an ornamental import. Its entrance to Minnesota was through Duluth, and has since been spreading south and west.
Hoary alyssum, another European native, is prevalent in roadside ditches. The main concern with this plant is that it is toxic to horses. Cattle, sheep,and goats seem to be unaffected by it, but severe adverse effects are seen in some horses. The specific toxin in the plant is unknown.
And a plant handy in an emergency
Common Mullein (Verbascum thapsus)
The leaves of this plant are large and soft, and its colloquial names include Camper’s Helper, Charmin of the woods, Fishermen’s Friend etc. I’m sure you get the idea.
Another interesting aspect of mullein is that historically it has been used to poison fish. Seeds of the mullein were ground up and thrown in lakes or ponds to create a “fish sting”. Its toxin caused fish to float to the surface where they could be easily scooped up by the “fishermen”. Of course this is now highly illegal.