Sium suave (Water Parsnip)

Plant Info
Also known as: Hemlock Water Parsnip
Family:Apiaceae (Carrot)
Life cycle:perennial
Habitat:sun; swamps, wet meadows, wet ditches
Bloom season:July - September
Plant height:2 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] Convex cluster (umbel) to 5 inches across made up of groups (umbellets) of 10 to 20 flowers each. Flowers are about 1/8 inch across with 5 white petals that are somewhat heart-shaped and may be of unequal size.

[photo of bracts] At the base of the umbel are 6 to 10 narrow bracts that curve down away from the cluster. Smaller bracts are at the base of each umbellet. Umbels form at ends of branches and upper leaf axils on stiff, 4 to 6 inch stalks.

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

[photo of leaves] Leaves are compound with 7 to 17 lance to linear leaflets, 2 to 5 inches long, ¼ to ½ inch wide, sheathing the stem and becoming smaller in the upper plant, typically with tiny, sharp teeth around the edges but occasionally smooth. Submersed basal leaves are double compound with feathery, bi-sected lobes. Stems are stout, typically single with marginal branching in upper plant, Both stems and leaves have smooth surfaces.

Fruit: Fruit type: seed without plume

[photo of fruit] Fruits is a somewhat flattened oval capsule about ¼ inch long, obviously ribbed, that splits into 2 seeds.


Water Parsnip is common along shallow, marshy streams and drainage ditches or scattered throughout open wet meadows. It often shares its habitat with 2 similar species: Water Hemlock (Circuta maculata), and Bulblet-bearing Water Hemlock (Circuta bulbifera), but the leaves easily distinguish the 3 species. C. maculata has double compound leaves with broad, flat, sharply toothed, stalked leaflets; C. bulbifera also has double compound leaves but the leaflets are narrow and nearly thread-like.

Please visit our sponsors

  • Minnesota Goose Garden

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens
  • Shop for native seeds and plants at!
  • Shooting Star Native Seeds - Native Prairie Grass and Wildflower Seeds

More photos

Photos by K. Chayka taken at Rice Creek Trail Regional Park, Ramsey County. Photos courtesy Peter M. Dziuk taken in Anoka and Polk counties.


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

Posted by: Jon - Boundary Waters Canoe Area- at the portage into Zephyr Lake
on: 2018-09-14 07:24:52

I thought this was Poison Hemlock at first, being unfamiliar with the plant, but doing some research upon my return, it appears to have been Water Parsnip.

Posted by: Gary - Carlton County
on: 2019-01-29 16:03:38

This species seems to do well in temporary forest ponds. Deer like to eat it.

Posted by: gary - Lake County
on: 2022-07-29 20:56:29

In a small vernal pond just off the Superior Hiking Trail between Finland and Little Marais. Some interesting sedges as well.

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.