Cicuta maculata (Water Hemlock)

Plant Info
Also known as: Spotted Water Hemlock, Spotted Cowbane
Genus:Cicuta
Family:Apiaceae (Carrot)
Life cycle:biennial, perennial
Origin:native
Habitat:part shade, sun; along shores, wet fields, moist thickets, wet ditches, fens, swamps
Bloom season:June - August
Plant height:3 to 6 feet
Wetland Indicator Status:GP: OBL MW: OBL NCNE: OBL
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 5-petals Cluster type: flat

[photo of flowers] Flat clusters (umbels) up to 6 inches across arising from leaf axils and at the end of branching stems, in small groups (umbellets) of 12-15 flowers with 10 or more umbellets in a cluster. Flowers are 1/8 inch across, have 5 white petals, notched at the tip, 5 long stamens and a greenish white center.

Leaves and stem: Leaf attachment: alternate Leaf type: compound

[photo of leaves and vein pattern] Double compound leaves may be well over a foot long in the lower part of the plant and much smaller at the top; each compound leaf has 3 or more leaflets. Leaflets are up to 4 inches long and 1¼ inches across with pointed tips and sharp teeth, and often fold up some from the central vein. A distinguishing feature of the leaves is the veins radiating from the central vein tend to terminate in the notch of the teeth instead of the tip. Stems are much branched, may be green or purple, or have purple streaks or spots.

Notes:

This is one of the most deadly poisonous plants in the U.S. to both humans and animals. Water Hemlock is easy to distinguish from other members of the Carrot family by the leaves, in particular the vein pattern. There are as many as 4 varieties in North America and according to USDA Plants, 3 of them are present in Minnesota, but the DNR only recognizes var. maculata here. The distinguishing features of the different varieties are poorly documented.

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More photos

Photos by K. Chayka taken at Rice Creek Trail Regional Park, Ramsey County. Photos courtesy Peter M. Dziuk taken in Anoka County and at Split Rock State Park, Lake County.

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Jody
on: 2009-07-25 00:33:02

My landscaper friend "consulted with ecologist Mary Reider with the DNR. She suggests pulling it if you are trying to foster diversity of species on your property."

and Mary McFadden-Lesar of the DNR wrote:
"Water hemlock 'Cicuta L.' may be a native plant but there is no reason why you have to allow it to thrive in your landscape. I, personally, would take Water Hemlock out of my landscape due to its toxicity to so many animals as well as humans."

One each for poisonous and weedy/invasive. Mine is drying in my firepit, awaiting the next bonfire.

Posted by: K Chayka
on: 2009-07-25 18:20:58

Thanks for the clarification!

Posted by: Leo - Along Hwy 61 N of Pine City MN in road ditch
on: 2015-07-20 22:40:16

Several patches of these between the RR tracks and Hwy 61, N of Pine City, MN. We pulled several out of our rented pasture land. We plan to dry and burn them.

Posted by: Patti - Kanabec County
on: 2016-05-16 16:20:50

This grows in the wetland areas on the outskirts of our woods. There is a very good reason to leave it grow, as it is a host plant for Swallowtail Butterflies. I taught my children to respect and avoid it.

Posted by: Ben - Along the bike trails from Lilydale through Mendota
on: 2016-07-21 07:29:41

We were biking along the trails starting at Harriett Island up to Mendota. We saw many examples of what looked like Water Hemlock on either side of the bike trail starting past the yacht club and becoming more prolific as we approached the scenic overlook just past Axels in Downtown Mendota

Posted by: K. Chayka
on: 2016-07-21 07:52:02

Ben, I suspect what you saw was not water hemlock, but a relatively new invasive species first seen in Lilydale in 2012 - Japanese hedge-parsley, Torilis japonica.

Posted by: Linda - Lebanon Hills Regional Park, Eagan
on: 2016-07-31 11:51:37

Have seen just 3 plants --2 on stream edge by first parking lot and one at beginning of Discovery Trail.

Posted by: Steve - Itasca county
on: 2016-08-12 11:49:13

Have seen this plant many times along roads from Bigfork to Grandrapids. Must be more common than I first thought. Have checked several sources and am positive of the identification. So Butterflies like them. I do not. Will kill them if on my property

Posted by: Amy N - Golden Valley
on: 2017-06-02 18:58:21

I'm pretty sure this is in my backyard growing along the edge of the woods.

Posted by: Terry B - Crosby
on: 2017-07-01 10:43:44

We've had these on our property for years - it's a native plant, we don't touch it and it has beautiful flowers. So I just take pictures of it and leave it alone.

Posted by: Melinda Goetsch - Co. Rd. 79 in Big Lake Twonship, Sherburne co.
on: 2018-07-01 16:42:34

about 1/2 mile from intersection of Co. Rd. 32 and Co. Rd 79 in ditch near some young evergreens

Posted by: Nancy Smith - Lakewood Township, outside Duluth
on: 2018-08-05 12:32:34

This year I realized that Wahl Road, outside Duluth, has maybe a dozen water hemlock plants scattered up and down the road. The hemlock has a distinctive pattern that stands out from the superabundant valerian, now that they're both flowering. The hemlock is pretty, but I'm considering yanking what I can find before it goes to seed. I've been awaiting a call from the Ag Extension office for further advice.

Posted by: Gary - Carlton County
on: 2019-01-29 15:54:15

I've noticed that a number of insects use Cicuta maculata including larvae of the Canadian swallowtail butterfly, several small beetles (feeding on pollen it appears), solitary bees, and wasps, such as Spilopteron franclemonti, which feed on pollen and nectar. Maybe it is not advisable to completely eradicate it? If every deadly poisonous plant were yanked out of the ground then there would not be many plants left in our Minnesota forests and fields and many species of wildlife would also become more scarce.

Posted by: K. Chayka
on: 2019-01-29 16:54:33

Nothing wrong with the native carrots even if they're poisonous, as far as I'm concerned. Just learn to recognize the toxic ones and don't eat them! If you're worried about kids, train them to recognize it, too. Sorry, but there is no help for domesticated dogs who eat anything and everything.

Posted by: Donna Turner - Circle Pines
on: 2019-07-31 17:52:10

It is growing and blooming in wet sand a few feet from Rice Creek where it flows out of Baldwin Lake in Baldwin Park. Anoka County. July 31, 2019. I have been walking there for years and this is the first time I have seen it. I am wondering if the seeds washed in from spring flooding as that area was submerged this year. There is another new plant there that I am unable to identify.

Posted by: Eva Knudsen - Oak Grove
on: 2020-07-17 09:02:40

Have this growing all over in the back wetland area. It has really expanded in the last couple of years. I try to remove only those along the border near the chicken coop.

Posted by: gary - Carlton County
on: 2021-07-17 21:51:53

Somewhat common in the sedge dominated wetlands on my property. I'd like to see more of it here as it is a host plant for the black swallowtail butterfly (Papilio polyxenes). The dislike for this plant that some have expressed seems misguided.

Posted by: Bonnie Graft - Cass County Thunder Lake
on: 2021-07-30 10:20:22

We have one large spotted water hemlock on our lake shore. Advice on removing it?

Posted by: Karen Kaehler - Cass/Crow Wing along the Old Grade aka County Road 54
on: 2023-07-01 20:06:38

There are of vast number of these growing all along the 10 mile stretch of the Old Grade. I did have some on my property near a small stream in Cass County but they appear to have disappeared.

Posted by: Kelly Barrett - Swatara
on: 2023-07-13 08:23:57

There is quite an extensive population along the ditches of 29, South of Swatara.

Posted by: K Chayka
on: 2023-07-13 14:03:15

At this time of year water hemlock is filling wet ditches all across Minnesota, particularly in the northern half of the state.

Posted by: Steven Richardson - Silver Creek Township/Lake County
on: 2023-07-20 08:13:04

This is in drainages along our road as well as wet low areas throughout our property. Is the toxicity an issue for casual contact? For example, if one just brushes by it and plant touches exposed skin. Had this land for years yet just recently identified this plant. Imagine I've come in contact with it on more than one occasion.

Posted by: K Chayka
on: 2023-07-20 18:26:48

Steven, casual contact should not be an issue like it is with wild parsnip.

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