Wild parsnip

Wild parsnip (Pastinaca sativa)

Herbaceous, monocarpic perennial. Grows as a rosette with upright leaves, persisting for at least 1 year. Flowering stems are stout, hollow, grooved, and up to 5’ tall.

Overview

Regulated areas of wild parsnip
Wild parsnip is Restricted (Orange counties)

Other names for this plant include:

  • Common names: parnsip
  • Scientific names: P. sativa var. pratensis

Ecological threat:

  • Invades prairies, oak savannas, and fens as well as roadsides, old fields, and pastures.
  • Broad habitat tolerance; grows in dry, mesic, or wet habitats, but it does not grow in shaded areas.

CAUTION: When sap contacts skin in the presence of sunlight, it can cause severe rashes, blisters, and discoloration of the skin (phytophotodermatitis). Wear gloves, long sleeves, and long pants when handling.

Classification in Wisconsin: Restricted

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for wild parsnip was based upon this literature review developed by the department.

Identification

Leaves: Rosette leaves are pinnately compound with 5-15 broad, ovate to oblong leaflets. Stem leaves are alternate, with 2-5 pairs of opposite, sharply toothed leaflets. Petioles wrap around the stem. Upper stem leaves are reduced to narrow bracts.

Flowers: Numerous, small, 5-petaled, yellow flowers in umbels 2-6” wide at the tops of stems and branches. Blooms from late spring to mid-summer.

Fruits & seeds: Seeds are flat, round, yellowish, and slightly ribbed. Seeds remain viable in the soil for 4 years.

Roots: Long, thick taproot.

Similar species: Wild parsnip can be confused with 2 native prairie species—golden Alexander (Zizia aurea) and prairie parsley (Polytaenia nuttallii). Golden Alexander is shorter and its leaves have only 3-7 leaflets. Prairie parsley leaves have few teeth and its flowers are rounded, not flat like wild parsnip.

Distribution

Known county distribution of wild parsnip
Counties in WI where wild parsnip has been reported (as of July 2011). Both vouchered and unvouchered reports included.

Do you have wild parsnip in your county but it isn't shaded on the map? Send us a report.

Control

Mechanical: Cut root at an angle 1-2” below soil surface. A brush-cutter can also be used for large populations before seeds set. Remove flowering heads and dispose of in landfill or by burning.

Chemical: Spot treat rosettes with 2, 4-D, metsulfuron methyl, or glyphosate. Spot treat adult plants mid-May to mid-June with metsulfuron methyl plus a surfactant.

For more information on control techniques, visit the Wild parsnip factsheet [exit DNR] by University of Wisconsin-Extension.

Photos

View wild parsnip pictures in our photo gallery!

Resources

Sources for content:

  • Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 2005. Pg. 70-72

Links for More Information

Last revised: Wednesday June 05 2013