Don't touch that plant. 6 vines, bushes, shrubs to avoid this summer in Michigan

Yahoo

10-06-2025

If you're heading outdoors this summer, it pays to know the difference between poison ivy, poison oak and other rash-producing plants that will leave you itching and scratching — or worse.
Most Michiganders are familiar with poison ivy in its various forms, but plants such as poison sumac grow in swampy areas, and invasive giant hogweed and wild parsnip can cause more significant, long-lasting health problems, according to state's Invasive Species Program.
"It can be difficult to determine whether you're looking at hogweed, hemlock or parsnip, but all of these plants have several things in common: contact may cause unpleasant, potentially deadly, reactions," the U.S. Fish & Wildlife Service said.
Poison ivy, poison sumac and poison oak can cause a red, bumpy rash from its transferred oils called urushiol. Ingesting other native Michigan plants, the nightshade plant for example, can be deadly in small doses, according to Michigan State University's Extension.
As residents explore the outdoors, here are six poisonous or toxic plants to identify and avoid:
The plants may be identifiable by their large size — they can grow up to 14 feet tall. Hogweed is native to Asia and typically grows in open areas, but can be spotted in various habitats, according to Michigan's Invasive Species Program, a joint effort of the departments of Environment, Great Lakes, and Energy; Natural Resources; and Agriculture and Rural Development.
Hodgweed is an invasive species in Michigan, but has become established in the state, the website notes.
The plants contain toxins called furanocoumarins. These are mostly found in the sap as well as throughout the plant's tissues, according to WebMD.
If you come in contact with the plant's sap, it can cause an allergic reaction called photo dermatitis or photo sensitivity: Your skin becomes sensitive to sunlight and may blister when exposed to light.
WebMD says you can develop symptoms in as little as 15 minutes. Severe cases can cause scarring for up to six years.
Getting the sap in your eyes can cause permanent blindness.
"The toxin is most problematic if it gets into your eyes. Immediately wash your eyes for 15 minutes straight if you think that they've been exposed," WebMD says.
Here's how to identify:
White flowers in an umbrella-shaped cluster up to 2.5 feet across.
Plant is 7 to 14 feet tall.
Stems are green with purple splotches and visible, coarse, white hairs.
Leaves are up to 5 feet wide, lobed and deeply incised.
In Michigan, there are two types of poison ivy growing throughout yards and forests: eastern poison ivy, which grows throughout the Lower Peninsula, and western poison ivy, which grows mostly in northern areas, including the Upper Peninsula, according to Michigan State University's Extension.
All poison ivy contains an oil called urushiol in the leaves, stems and roots of the plant, the Mayo Clinic said. When touched, the oil creates an allergic reactions in the form of a red rash.
All poison ivy (western and eastern species) has certain qualities, MSU Extension and the American Museum of Natural History say, including:
The stalk of the middle leaflet is much longer than the stalks of the two side leaflets.
Surface of the leaves can be glossy or dull.
There are three leaflets, and the edges can be smooth or coarsely toothed. Some have a prominent "thumb-like" lobe.
The leaf arrangement alternates.
In the fall, leaves turn turn red with some yellow.
Greenish flowers appear with five petals about 3 millimeters in diameter. Flowers appear in loose branching clusters and arise from where the branch or leaf attaches to the stem.
Berries/fruits appear in loose drooping clusters and contain a single seed, and are hard and whitish.
Western poison ivy grows upright and does not have aerial roots. The plants grow in patches on the ground.
Eastern poison ivy grows as either a plant on the ground or as a vine on trees or buildings with aerial roots to secure itself around trees or other objects.
Poison oak is a relative to poison ivy that contains the same oils and is extremely common in California. There are two types of poison oak plants, Pacific poison oak and Atlantic poison oak.
Pacific poison oak grows in the western U.S. in a wide range of habitats ranging from grasslands to forests. Atlantic poison oak grows in southeastern U.S. and is usually found in open woodlands and sandy thickets. Neither type typically grows in Michigan.
Poison oak's leaves resemble an oak leaf, but at times have jagged edges, according to the Santa Lucia Conservancy, based in Carmel, California. Like poison ivy, its leaves have a alternate leaf pattern. It can grow as a shrub, bush or vine.
In the spring, poison oak's leaves appear shiny with reddish or green colors that can curl inward. As the plant grows, the leaves increase in size and are bright to dark green.
In late spring they bloom small, star-shaped, yellow flowers in clusters on its stem.
Like giant hogwood, wild parsnip is an invasive species in Michigan and has been detected in the state, according to Michigan's Invasive Species Program.
The plant is a flowering herb that grows up to 5 feet tall with yellow-to-green flowers shaped like umbrellas that grow in clusters. It has toothed leaves with leaflets that grow across from each other from the smooth, green stem. The flowers bloom in June and July.
When touched the plant's harmful chemicals can cause a rash and blisters, and can cause the infected area to become sensitive to sunlight.
"Wild parsnip spreads aggressively through seeds carried by wind, water and equipment. Stem, leaves, and flowers contain chemicals that can increase skin sensitivity to sunlight and cause severe rash or blistering. Plant chemicals are known to reduce weight gain and fertility in livestock that eat wild parsnip," according to the invasive species website.
If you find wild parsnip growing in Michigan, state officials urge you to report the sighting through the Invasive Species Information Network online reporting tool.
A relative to poison ivy, poison sumac is a flowering shrub or woody plant that contains the same oil. However, it is considered more allergenic, causing a very inflamed, painful and itchy rash.
Poison sumac has alternate compound leaves with pointed, shiny leaflets and a red stem. The woody plant grows to 15 feet tall and has bark that is a dull gray.
Sumac has a red stem sprouting from a grey bark stem. In June, clusters of small, green flowers bloom, based on MSU's Department of Entomology.
Poison sumac is typically found in fens and indicates wet soil, MSU said. It can be found in swampy areas throughout most of the Lower Peninsula.
Poison hemlock can be extremely poisonous to animals and humans if ingested. All parts of the plant are poisonous and made up of toxic compounds called "conine, g-coniceine and related piperidine alkaloids," according to the U.S. Agricultural Research Service.
This plant is also referred to as deadly hemlock, poison parsley, spotted hemlock, European hemlock, and California or Nebraska fern.
It blooms in the spring (when they are particularly toxic) throughout the U.S.
Here are some ways to identify the plant:
White flowers that grow in small erect clusters — each flower develops into a green fruit with seeds.
Grows along fence lines, in irrigation ditches, and in other moist waste places.
Leaves are delicate, like parsley, and have a white taproot — the main root of the plant.
Can grow to be 6.5 to almost 10 feet tall.
Hollow stem usually marked with small purple spots.
Contact Sarah Moore @ [e-mail]
This article originally appeared on Lansing State Journal: Poisonous plants in Michigan: Hogweed, poison ivy, sumac, more