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Sium suave (Hemlock waterparsnip)
Smith, R.W.

Sium suave

Sium suave Walter

Hemlock Waterparsnip, Water Parsnip

Apiaceae (Carrot Family)

Synonym(s): Sium cicutifolium, Sium floridanum, Sium suave var. floridanum

USDA Symbol: SISU2

USDA Native Status: L48 (N), AK (N), CAN (N)

Fragrant, sometimes aquatic plant with flat clusters of tiny dull-white flowers and strongly ridged stems.

The roots of this plant can be boiled and eaten as a cooked vegetable, but because of the plant's resemblance to the deadly Water Hemlock (Cicuta maculata), they are best left alone.


From the Image Gallery

1 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Fruit Type: Schizocarp

Bloom Information

Bloom Color: White
Bloom Time: Jul , Aug , Sep


USA: AK , AL , AR , AZ , CA , CO , CT , DC , DE , FL , GA , IA , ID , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , MT , NC , ND , NE , NH , NJ , NV , NY , OH , OR , PA , RI , SC , SD , TN , TX , UT , VA , VT , WA , WI , WV , WY
Canada: NB , NL , NS , ON , PE
Native Distribution: Throughout East, except Arctic; also in much of West.
Native Habitat: Wet meadows and thickets, muddy shores.

Growing Conditions

Soil Moisture: Moist , Wet


Use Other: Some tribes believed that smoke from common water-parsnip seeds could drive away evil spirits trying to steal a hunter's luck. (Kershaw)

Water-parsnip is so similar to its highly poisonous relatives (such spotted water-hemlock), it is better left alone. (Kershaw)
Conspicuous Flowers: yes
Fragrant Flowers: yes

Value to Beneficial Insects

Supports Conservation Biological Control

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

Additional resources

USDA: Find Sium suave in USDA Plants
FNA: Find Sium suave in the Flora of North America (if available)
Google: Search Google for Sium suave


Record Modified: 2014-06-14
Research By: TWC Staff

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