Cicuta maculata

Spotted Water Hemlock

Spotted Water Hemlock, Photo courtesy USDA Plants Database and William S. Justice
Spotted Water Hemlock
Photo courtesy USDA Plants Database
and William S. Justice

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Cicuta, Latin for "hemlock, poison from the hemlock"
  • maculata, Latin for "spotted"
  • Spotted Water Hemlock, from the purple-mottled stem base
  • Other common names include: Water Hemlock, Common Water Hemlock, Spotted Cowbane, Musquash Root, carotte à Moreau (Qué), Linnéherbariet (Swe)


  • Kingdom Plantae, the Plants
    • Division Magnoliophyta, the Angiosperms (flowering plants)
      • Class Magnoliopsida, the Dicotyledons
      • Subclass Rosidae
        • Order Apiales
          • Family Apiaceae (Umbelliferaceae), the Parsley and Carrots, 2850 species in 275 genera of global distribution but mostly north temperate regions. Includes the common herbs anise, carrot, celery, coriander, dill, fennel, parsley, and parsnip, as well as the highly toxic hemlocks.
            • Genus Cicuta, the Water Hemlocks
  • Taxonomic Serial Number: 29456
  • Family Apiaceae characterised by alternate leaves, widening at the base into a sheath that clasps the stem. Stems often furrowed. Flowers usually compound, almost always concentrated in flat-topped umbels. Flowers have 5 petals, usually uneven, and 5 stamens. Seeds and fruit form below where the petals and stamen originate. Fruit two-chambered, separating into two, single-seed fruits at maturity. Some part of the plant usually has a strong aroma, due primarily to various oils produced by the plant.


  • A coarse, stout, wetland perennial, 20"-80" tall
  • Leaves alternate, compound, twice or thrice divided, with petioles that partially sheath the stem. Uppermost leaves not dissected. Oblong to ovate in general outline, these compound leaves run 3"-10" long and 2"-6" wide. Basal leaves larger and with longer petioles than cauline leaves. [Photo]
  • Leaflets linear to broadly lanceolate, pointed at the tip, rounded or tapering to the base, mostly 1"-4" long, ¼"-1¼" wide, hairy, with regularly pointed and notched edges. Leaflet veins extend into or near the notches of the leaf rather than in the points.
  • Stems solitary or few together from a tuberous-thickened and chambered base, conspicuously hollow above the base. Erect, branched, each about 2" long. hairy, up to 7' tall. Often has a purple striped or mottled stem base. glabrous, hollow stems Stems are smooth, branching, swollen at the base, purple-striped or mottled, and hollow except for partitions at the junction of the root and stem. with cross-partitions at the nodes and many of these at the base of the stem
  • A yellow, oily, highly toxic liquid smelling like parsnips exudes from cut stems and roots.
  • Roots partly tuberous, in dahlia-like clusters of 2 to 8 fleshy roots, each about 2" long, with a scent of parsnip.
  • Flowers white, many; in compound, flat-topped, umbrella-like clusters at ends of stems and branches.
    • Sepals 5, green, triangular.
    • Petals 5, free, white, about 1/10" long.
    • Ovary inferior (below flower)
  • Fruit small, dry, nearly spherical, smooth but with prominent corky ribs; up to ¼" long. Ripening July-September.


  • A waterside plant
  • Identifiable as one of the Apiaceae by its broad, flat flower clusters, hollow stem, and clasping leaves.
  • Distinguished from all other similar species by its compound leaves divided into leaflets more than ½" broad, its large umbels of white flowers, its smooth fruits, and axils not bearing bulbils.
  • Similar plants:
    • Poison Hemlock (Conium maculatum) is a highly toxic exotic (Socrate's bane) which does not occur in the BWCA area but has become naturalised through much of the eastern US. Poison Hemlock leaves are heavily dissected and fernlike, as opposed to the lanceolate leaflets with sharply-toothed edges of Spotted Water Hemlock.
    • Bulb Bearing Water Hemlock (Cicuta bulbifera) has narrow leaflets, bulbils in the leaf axils, and lacks purple mottling on the stem.
    • Water Parsnip (Sium suave), is not poisonous and has toothed lanceolate leaflets.
    • Cow Parsnip (Heracleum maximum) has large palmate leaves rather than toothed, compound leaves.


  • Alaska to Quebec, south to Florida, Texas, and California, into northern Mexico.


  • Edges of ponds, lakes, and streams; shallow waters. Also wet meadows, marshes, swamps, springs, roadside ditches, and other wet places.



  • Boneset (Eupatorium perfoliatum), has been prescribed as a folk medicine antidote for the poison of the Water Hemlock.


  • POISON. All parts are considered poisonous to most animals; the amount of root that must be eaten to cause death is very small. Botanically related to the infamous Poison Hemlock but toxicologically different.
  • Very poisonous alkaloid and resinoid (Cicutoxin and cicutolare) found in all parts of the plant, primarily in the roots but also in the pithy area between the nodes. Cicutoxin is a yellow, viscous resin with a carrot-like odor, which affects the central nervous system.
  • Considered most violently toxic plant in North America. Humans and livestock are susceptible to poisoning and death after ingesting plant material. The onset of symptoms is often so sudden and traumatic that treatments are not always successful. Symptoms include salivation, muscle spasms, violent convulsions, coma, and death from respiratory failure. Death reported to occur in as little as 15 minutes to 2-3 hours after a lethal dose.
  • Roots may be mistaken for wild parsnip or artichoke and humans have been killed after only one or two bites of what they thought were "parsnips" (water hemlock root resembles a parsnip).
  • All animals can be affected, but cattle are especially at risk, hence the name "cowbane", as the plant grows in soil which is wet and damp, enabling the animal to easily pull up the plant. Most cases occur in the springtime when the plants are smaller and apparently more palatable and the roots are easily pulled up.
  • Animals may also be poisoned if water hemlock is plowed under or if ground is reclaimed, since this may expose the root. Toxicity decreases through the growing season, and the toxicity of above-ground parts may be negligible when dry. The roots however are toxic at all times, even when dry. Animals have been poisoned by drinking water that had been contaminated with trampled water hemlock roots.
  • Wash your hands after handling this plant.


  • Reproduces by seed and vegetatively
  • Flowers June-September


  • By seed or division


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Full sun
    • Muddy soil
    • Wet soil to 6" water depth.
  • Size 30"H
  • Rarely cultivated due to toxicity.



  • We've found this one in bloom along the shore at BWCAW campsites.

Valley Internet Company
Return to Home Page
Send Feedback to Webmaster

Last updated on 26 February, 2004