ENVIRONMENT

Poison hemlock is invading Indiana. It's not alone. These 5 poisonous plants are too.

London Gibson Sarah Bowman
Indianapolis Star

There’s a new invasive plant frequenting Indiana’s roadsides, and although comprised of bunched, dainty white flowers and slender stems reaching as high as 6 feet tall, it’s also acutely poisonous to taste and touch. Poison Hemlock is spreading throughout the Hoosier State. 

The plant, a member of the carrot family, is toxic from the seeds to the flowers and the stem. Although it’s been around for several years in Indiana, it’s only been in the last few years that its presence has “exploded,” experts say.

Poison hemlock favors roadsides, railroad right-of-ways and other developed, human-disturbed areas. Although touching the plant is likely to create some mild skin irritation, ingesting the plant can be fatal for humans and animals.

If you find a plant matching poison hemlock’s description in your backyard, don’t fret: It’s possible to safely remove it. For guidance on how to do so, check out this story from IndyStar. 

But poison hemlock isn’t the only poisonous plant lurking in Indiana’s natural spaces. Here are six poisonous plants you should keep an eye out for.

Deadly invasive weed:It's moving into Indiana's parks, flower beds and backyard gardens

Umbrella-like flower clusters similar to Queen Anne's lace are one way to recognize the hazardous weed poisonous hemlock.

Poison hemlock

Poison hemlock grows between 4-9 feet high, and resembles a large Queen Anne’s Lace. It has fern-like leaves and purple-splotched stems topped with bunches of small white flowers.  

The plant is toxic to animals and humans that eat it, and prefers to grow in developed spaces such as along roadsides. Compared to other invasive species in Indiana — like honeysuckle and Bradford pear — it’s not as much of a threat to ecosystems. 

Cow Parsnip

Cow parsnip

Cow parsnip is only slightly shorter than poison hemlock, reaching its maximum height at about 5-8 feet high. Its stem is ridged, with fuzzy hairs. Cow parsnip’s flowers are also white with clusters, but its leaves are thicker and about 2-2½ feet across.

The plant also grows along roadsides, but unlike poison hemlock, cow parsnip is also found in woodlands and grasslands. The sap of cow parship can cause rashes or burns when exposed to skin. 

Wild parsnip growing along a road.

Wild parsnip

Wild parsnip, a smaller relative to cow parsnip, grows about 5 feet tall and has thin, yellow-green stems. Its stalks are topped with clusters of yellow flowers, similar to those of cow parsnip and poison hemlock except for the color. 

Wild parsnip also produces chemicals that burn skin and can create severe blistering, especially in the sunlight. It’s found in every continental state in the U.S. except for Florida, Georgia, Alabama and Mississippi.

Poison ivy off trail in the Charles C. Deam Wilderness, south of Bloomington, Tuesday, June 23, 2020.

Poison ivy

A famously itch-causing plant, poison ivy can be found in multiple environments, from roadsides to backyard flower beds. The plant has leaves made of three-leaflet bunches with smooth or scalloped edges.

All parts of the plant secrete an oil that affects human skin, and touching poison ivy can cause blotching, blisters, itching and pain.

Poison sumac grows in swampy areas, primarily in the northern part of the state.

Poison sumac

While poison sumac is mostly found in the northeastern part of the state, the plant loves to live in swamps, bogs and wet areas.  The plant has red-hued stems and elongated leaves that end in a 'V,' that change in color from bright orange in the spring to green in the summer and red-orange in the fall. It also has small, yellowish clusters of flowers.

The oil in poison sumac makes all parts of the plant toxic, and creates symptoms such as itchiness, burning, redness and blistering. 

Stinging nettle.

Stinging nettle

A plant that frequents riverbanks and wooded areas, stinging nettle can grow as tall as 6ix feet. Its toothed leaves and stems are covered in thin hairs that cause the stinging. It also has small white or green flowers.

When the hairs on the plant come into contact with skin, it creates an itchy rash that looks like raised bumps in the skin or hives. Some people may also have an allergic reaction to stinging nettle that can be life-threatening.

Contact IndyStar reporter London Gibson at 317-419-1912 or lbgibson@gannett.com. Follow her on Twitter @londongibson

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IndyStar's environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.