Sium suave

Species Native to Missouri
Common Name: water parsnip 
Type: Herbaceous perennial
Family: Apiaceae
Native Range: North America
Zone: 3 to 9
Height: 2.00 to 6.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: July to September
Bloom Description: White
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Rain Garden
Flower: Showy
Tolerate: Wet Soil


Grow in consistently moist to wet soils, including shallow standing water, in full sun to part shade. Plants will self-seed in optimum growing conditions. Rootstock can be divided in early spring.

Noteworthy Characteristics

Sium suave, commonly known as water parsnip or water parsley, is a water-loving perennial of the carrot family that is native to swamps, wet meadows, wet woodlands, stream/pond margins, roadside ditches and muddy shores throughout North America (Newfoundland to British Columbia south to Florida, Texas and California). Each plant typically grows to 2-6' tall (spread of 2-3') on a stout, hollow, central stalk clad with pinnately compound deep green leaves (to 4-10" long). Each leaf is divided into 7-17 pointed lanceolate leaflets (to 4-5" long) with toothed margins. Water parsnip often grows in shallow water, with its submerged leaves divided into thread-like segments. Tiny white flowers bloom in summer (July-September) in domed umbels (to 2-3" wide) subtended by narrow leaf-like bracts. Flowers are followed by small, ribbed, oval fruits.

Genus name comes from an ancient Greek name sion applied to some water plants.

Specific epithet comes from Latin suavis meaning sweet.


No serious insect or disease problems.


Native plant for wet areas of the landscape. Water gardens. Pond margins. Roots can be eaten as a vegetable (boiled), but this is not recommended because of the similarity of this plant to Cicuta maculata (water hemlock) which is extremely poisonous.