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Western Water-hemlock - Cicuta douglasii

Native Species

Global Rank: G5
State Rank: S4
C-value: 4


Agency Status
USFWS:
USFS:
BLM:


 





 
General Description
Stems erect, 30–100 cm. Leaves basal and cauline; leaflets lanceolate to ovate, serrate, 15–60 mm long; tertiary venation enclosing sections of leaf ca. twice as long as wide, reticulations often not meeting each other. Umbels terminal and axillary; rays 1–5 cm long. Mericarps 2–4 mm long; dorsal ribs wider than the darkened intervals (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Diagnostic Characteristics
Whether by name or look, several members of the Apiaceae (Carrot or Parsley) Family can be look-a-likes. These plants are not ones to mis-identify because some are toxic or poisonous. Be conscious of your safety when examining plants. Keep in mind that other species - not listed below - may also be perceived as look-alikes!

Western Water-hemlock - Cicuta douglasii, native
* Plants: Highly poisonous. Hairs absent (glabrous).
* Stems: Often branched. Lower portion not purple-spotted. Base is swollen.
* Leaves: Glabrous. Bi- to tri-pinnately divided. Tertiary venation twice as long as wide and enclosing sections of the leaflets. Primary lateral veins terminate in the sinuses between the serrations (teeth). No bulbs in leaf axils.
* Flowers: white or greenish.
* Mericarps: Glabrous. Prominent ribs are corky (at least as wide as the darkened intervals), but not winged.
* Roots: Thickened or tuberous. Internally are horizontally divided with cross partitions.
* Habitats: Moist meadows, streambanks, and wetlands.

Bulb-bearing Water-hemlock - Cicuta bulbifera, native
* Plants: Highly poisonous. Hairs absent (glabrous).
* Stems: Usually solitary. Lower portion not purple-spotted. Base is swollen.
* Leaves: Glabrous. Upper leaves are simple or once-pinnate with bulblets in the axils.
* Flowers: White. Often sterile.
* Mericarps: Ribs thick and raised, wider than the intervals.
* Roots: Thickened or tuberous.
* Habitats: Fens.

Spotted Water-hemlock - Cicuta maculata, native
* Plants: Highly poisonous. Hairs absent (glabrous).
* Stems: Often branched. Lower portion not purple-spotted. Base is swollen.
* Leaves: Glabrous and bi- to tri-pinnately divided. Tertiary venation of the leaflet is as long as wide. Primary lateral veins terminate in the sinuses between the serrations (teeth). No bulbs in leaf axils.
* Flowers: White or greenish.
* Mericarps: Glabrous. Prominent ribs are corky (at least as wide as the darkened intervals), but not winged.
* Roots: Thickened or tuberous. Internally are horizontally divided with cross partitions.
* Habitats: Moist meadows, woodlands, streambanks, and wetlands.

Poison Hemlock - Conium maculatum, non-native
* Plants: Highly poisonous. Hairs absent (glabrous).
* Stems: Lower portion is purple-spotted. Base is little, to not, swollen.
* Leaves: Glabrous and tri-pinnately divided into small ultimate segments; fern-like. Veins meet with tip of the leaf's tooth. No bulbs in leaf axils.
* Flowers: White. Sepals absent.
* Mericarps: Glabrous, prominent ribs raised, but barely winged and often wavy.
* Roots: Stout taproot.
* Habitats: Moist, disturbed places, such as along streams, ditches, and cool open slopes.

Queen Anne's Lace or Wild Carrot - Daucus carota, non-native
* Plants: Hairs sparse (glabrate) to long and stiff (hirsute).
* Stems: Lower portion not purple-spotted. Base is not swollen.
* Leaves: Glabrous and bi-pinnately divided with leaflets being deeply divided. No bulbs in leaf axils.
* Flowers: White with the central flower of the central umbel often purple. Sepals minute.
* Mericarps: Ribs with barbed prickles (not glabrous).
* Roots: Stout taproot.
* Habitats: Along roads, trails, and in fields – often in areas with some disturbance.

Hemlock Water-parsnip - Sium suave, native
* Plants: Hairs absent (glabrous).
* Stems: Solitary. Lower portion not purple-spotted. Base is not swollen.
* Leaves: Glabrous. Emergent leaves are once-pinnate with lance-linear leaflets. Submerged leaves are bi- to tri-pinnately divided with narrower leaflets. Primary lateral veins sometimes terminate in the tips of the serrations (teeth). No bulbs in leaf axils.
* Flowers: White or greenish. Sepals minute.
* Mericarps: Glabrous and elliptical. Ribs corky, but not winged.
* Roots: Fibrous. Internally are horizontally divided with cross partitions.
* Habitats: In shallow fresh water and banks of streams, ponds, and wetlands.

Cow-Parsnip - Heracleum lanatum, native
* Plants: Hairs present.
* Stems: Single, hollow, with short, soft hairs (pubescent). Lower portion not purple-spotted. Base is not swollen.
* Leaves: Veins pubescent. Leaves once-palmately divided into 3 leaflets. Leaflets broad, 3-7 lobed, and coarsely toothed. Petioles are basally dilated. No bulbs in leaf axils.
* Flowers: White and sweet-smelling. Sepals minute.
* Mericarps: Glabrous. Obovate. Dorsal ribs narrow. Marginal (lateral) ribs broadly winged.
* Roots: Stout taproot.
* Habitats: Moist places, such as avalanche slopes, thickets, open forests, woodlands, along streams, and drier wetlands.

Hemlock Parsley - Conioselinum scopulorum, origin and presence unknown
* Plants: Sparsely hairy (glabrate).
* Stems: Single but sparingly branched and hollow. Lower portion not purple-spotted. Petioles are basally dilated. Base is not swollen.
* Leaves: Glabrate, bi- to tri-pinnately divided. Ultimate leaf lobes with one main vein. No bulbs in leaf axils.
* Flowers: White. Sepals absent.
* Mericarps: Glabrous. Elliptical. Dorsal ribs narrowly winged, low and corky. Marginal (lateral) ribs winged.
* Roots: Tuberous and fibrous.
* Habitats: Moist meadows, woodlands, streambanks, and wetlands.

Species Range
Montana Range Range Descriptions

Native
 


Range Comments
AK to CA, NV, ID and MT (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 117

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Wet meadows, marshes, along streams, wetlands; valleys, montane (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Ecology
POLLINATORS
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus impatiens (Colla and Dumesh 2010).


References
  • Literature Cited AboveLegend:   View Online Publication
    • Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141:39-68.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Culver, D.R. 1994. Floristic analysis of the Centennial Region, Montana. M.Sc. Thesis. Montana State University, Bozeman. 199 pp.
    • Eggers, M.J.S. 2005. Riparian vegetation of the Montana Yellowstone and cattle grazing impacts thereon. M.Sc. Thesis. Montana State University, Bozeman, MT. 125 p.
    • Heywood, V.H. 1971. The biology and chemistry of the Umbelliferae. Academic Press, New York.
    • Jones, W. W. 1901. Preliminary flora of Gallatin County. M.S. Thesis. Bozeman, MT: Montana State College. 78 pp.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
    • Stoecker, R.E. 1967. A population study of five species of small rodents in the Bridger Mountains of Montana. M.Sc. Thesis. Bozeman, Montana: Montana State University. 32 p.
    • Tuinstra, K. E. 1967. Vegetation of the floodplains and first terraces of Rock Creek near Red Lodge, Montana. Ph.D dissertation. Montana State University, Bozeman 110 pp.
  • Web Search Engines for Articles on "Western Water-hemlock"
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Citation for data on this website:
Western Water-hemlock — Cicuta douglasii.  Montana Field Guide.  .  Retrieved on , from