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Wild parsnip

(Pastinaca sativa)

Photo of wild parsnip
Photo credit: Wisconsin DNR

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

Overview map of wild parsnip classification in WI
Restricted (orange) counties

Other names for this plant include:

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

Classification in Wisconsin: Restricted

Ecological Threat
  • Invades prairies, oak savannas and fens, 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 sunlight, it can cause severe rashes, blisters, and skin discoloration (phytophotodermatitis). Wear gloves, long sleeves and long pants when handling.
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 four years.

Roots: Long, thick taproot.

Similar species: Wild parsnip can be confused with two 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.

Control

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

Chemical: Spot-treat rosettes with 2, 4-D, metsulfuron-methyl or glyphosate. Spot treat adult plants from 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 the University of Wisconsin-Extension.

Resources
Sources for content:
  • Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. The University of Wisconsin Press. 2005. Pg. 70-72
Links for more information: