Conium maculatum (Poison Hemlock)
| Also known as: | |
|---|---|
| Genus: | Conium |
| Family: | Apiaceae (Carrot) |
| Life cycle: | biennial |
| Origin: | Europe |
| Status: |
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| Habitat: | sun; moist soil, along shores, fields, roadsides, disturbed soil |
| Bloom season: | June - August |
| Plant height: | 3 to 8 feet |
| Wetland Indicator Status: | GP: FACW MW: FACW NCNE: FACW |
| MN county distribution (click map to enlarge): |  |
| National distribution (click map to enlarge): |  |
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Detailed Information
Flower: 
![[photo of flowers]](/udata/r9ndp23q/white/poison-hemlock_0701_085312.jpg)
Flowers are in flat clusters (umbels) about 3 inches across. Individual flowers are about 1/8 inch across and have 5 white petals of unequal size, usually notched and folded lengthwise. There are 5 stamens with white to yellowish tips, 1 between each petal. One plant has many clusters, at the ends of branching stems. The stems persist through the winter.
Leaves and stem:
![[photo of leaves]](/udata/r9ndp23q/white/poison-hemlock_0701_085625.jpg)
Leaves are 2 or 3 times compound, up to 12 inches long and wide, generally triangular in outline, becoming smaller as they ascend the stem. Leaflets are divided and fern-like, to 2 inches long and 1 inch wide.
![[photo of stem]](/udata/r9ndp23q/white/poison-hemlock_0617_154651.jpg)
The main stem is light green and covered in purple spots
Fruit:
![[photo of fruit]](/udata/r9ndp23q/white/poison-hemlock_0713_095103.jpg)
Fruit is an egg-shaped pod, about 1/8 inch long, covered in wavy ribs. It splits into 2 seeds.
Notes:
All parts of Poison Hemlock are deadly poisonous. This plant is easy to distinguish from other members of the carrot family by the feathery, double compound leaves, and the purple spotted stem.Native Plant Nurseries, Restoration and Landscaping Services ↓
Map of native plant resources in the upper midwest
More photos
Poison Hemlock plant, about 6 feet tall
stems from the previous year Photos taken at Long Lake Regional Park, New Brighton, MN July 2007 and June-July 2008
Comments
Have you seen this plant in Minnesota, or have any other comments about it?
on: 2011-06-04 13:48:01
Found on both sides of the path leading to Marnie St from the southwest corner of the park, a couple hundred feet from the street.
on: 2011-06-18 12:42:54
Based on the images you sent, I would say what you found was Not poison hemlock after all, but sweet cicely. Many members of the carrot family have similar leaves, i.e. deeply divided and a bit feathery. Queen Ann's lace and Japanese hedge parsley are others. Looking at various plant parts and paying attention to small details can help narrow down an ID.
on: 2012-03-24 11:02:32
Chayka is right about them being sweet cicely and not poison hemlock one easy way to identify this plant is its mouse urine like smell
on: 2015-07-01 12:57:29
I believe I've located this plant on the north side of Lake Shady along 5th ST. N.W. The approximate size of the patch is 10' x 10' I have pics if you'd like to confirm my findings. Zed
on: 2015-07-05 10:00:38
Zed, there are a number of carrot species with similar flowers and growth habits. We prefer you post pictures on our Facebook page if possible, that way others can learn from it, too.
on: 2017-07-02 16:01:34
Katy, thank you for your comments above. I was trying to figure out a new plant that was showing up in our yard (St. Paul) this year. Looking at my wildflower guide, it seemed to be poison hemlock. But then I checked your website and figured out that it's Japanese Hedge Parsley. I will pull it out.
on: 2017-07-07 16:16:42
I found and took pictures of several suspect plants on the walking paths around Rosemount High School. I believe this to be Poison Hemlock.
on: 2017-07-07 16:38:40
John K, while poison hemlock is rapidly spreading in MN, it is not the only non-native white carrot found in disturbed areas such as along paths. Poison hemlock has more recently been seen traveling along waterways, though it is also found along transportation corridors such as railroad rights-of-way. More common in the Metro area is Torillis japonica, Japanese hedge-parsley, which is becoming common in wooded parks.
Poison hemlock is quite robust, growing over 6 feet tall with a smooth, stout, purple spotted stem, hairless leaves and hairless, ribbed seeds. Japanese hedge-parsley is 3-4 feet tall with a hairy stem, hairy leaves, and fruit with hooked hairs.
on: 2017-08-03 19:00:31
Along the St. Louis River trail near Perch Lake in far west Duluth. Also on state or county forest land southwest of Hwy 23 near Hwy 18 in the Wrenshall area. In addition, some very large plants in there look like Giant Hogweed. There are also a few small p. hemlock plants growing on a trail off Hwy 210 N/NW of Hwy 23.
on: 2017-08-04 17:51:16
Susan, there are no confirmed occurrences of giant hogweed in Minnesota. The common cow parsnip (Heracleum lanatum)is often mistaken for giant hogweed and that is more likely what you found. Poison hemlock is being tracked in MN. You can open an account and post your finding at EDDMapS but you must include photos that can confirm it is what you think it is. Images showing the finely divided leaves and purple-spotted stem are best. There have been quite a number of mid-IDs for these plants. Confirmation is necessary.
on: 2018-04-26 14:35:52
found along County round 3 between Janesville and Waldorf MN last summer/Fall. Lots of it. Waseca County.
on: 2018-04-26 16:01:00
Carmen, we discovered poison hemlock is starting to run rampant in southeast and south-central MN. There are vast populations traveling along the Root River in Fillmore County. It seems there is no stopping it now. :-(
on: 2018-12-16 19:00:10
I seem to recall seeing some in Duluth along the boardwalk. This was in the late 2000's or early 2010's. I saw the plant growing in abundance in Missouri more recently and the growth form, purple mottling of the stem, leaves, etc. all were exactly what I remembered seeing in Duluth.
on: 2022-07-28 09:53:56
Found a patch along some railroad tracks just north of Highway 14 in northwest Rochester.
on: 2024-09-07 19:59:18
Found along the Paul Bunyan trail, abundant on west side of trail from Jenkins through pine river. Found in wetter areas along ditch.