Topics on this page:
- About wild parsnip
- Identification
- How to locate
- Phenology overview
- Phenophases - "show me what to look for"
About wild parsnip
Wild parsnip is a invasive plant in North America. It is the same species as the familiar food crop. Therefore, it is important that gardeners prevent parsnip from going to seed. Once naturalized, wild parsnip can cause a variety of harms. In addition to degrading natural habitats and crowding out native plants, it is a health danger for people. Its sap causes severe skin burns (click for safety information) and this toxicity also affects livestock.
Always wear long sleeves, long pants and gloves that protect the skin from contact with the sap of this plant.
Identification
Description: Wild parsnip grows to heights of ~5 feet tall and requires full or partial sun. Characteristic of the carrot family, its alternate leaves are pinnately compound. Leaflets are coarsely and irregularly toothed with an overall diamond shape. In the 2nd or 3rd growing season, plants develop hollow, grooved stems. The branched stems support flowers arranged in umbels, with five curled petals, chartreuse-yellow in color. Wild parsnip reproduces by seed, which are small, broad, oval and slightly ribbed. Individual plants dies after producing seeds, but usually, infestations persist.
Notes about the video: Mark Renz states that wild parsnip is restricted in Wisconsin. In Minnesota, wild parsnip is a Noxious Weed on the Prohibited-Control list. Mark Renz mentions weeding. Volunteers with Pesky Plants do not touch or remove plants.
Be aware of look-alike plants:
- Golden alexanders is a native plant that is commonly confused with wild parsnip. See page 62 of the MnDOT Noxious Weed Book.
- Water hemlock is a native plant that can be confused with wild parsnip. See page 72 of the MnDOT Noxious Weed Book.
- Poison hemlock is an invasive plant that can be confused with wild parsnip. It is on the Prohibited-Eradicate list in Minnesota. See page 17 of the MnDOT Noxious Weed Book.
More resources on identification:
- Wild parsnip profile page by Minnesota Department of Agriculture
- Wild parsnip profile page by Minnesota Department of Natural Resources
- Identify wild parsnip by University of Minnesota Extension
- Wild parsnip identification training module (Midwest Invasive Species Information Network)
- Minnesota Noxious Weeds Book (PDF, page 30, Minnesota Department of Transportation)
Wild Parsnip Identification and Reporting by U MN Extension.pdf
Locate a wild parsnip plant to observe
Proximity: As a volunteer, you will want to locate and track wild parsnip close to where you live, work, or regularly visit. Planning ahead will make future observations easy. Below are tips and tools to help you search your local environment for pesky plants to track.
Access to sites: Wild parsnip often grow on public domain lands, such as edges of sidewalks, bike paths, and roads. Exercise caution and sound judgement when observing plants on public domain lands. You can also locate these plants growing on public lands, such as parks and nature reserves. Follow these guidelines for getting permission to make observations on public lands. Do not enter others' private property without permission.
Habitat:
- Wild parsnip does not do well in shady areas so look for open, sunny habitats.
- Target your search along roads, paths, and rail right-of-ways.
- Areas that have been restored or intentionally planted with pollinator-friendly plants are less likely to contain wild parsnip. Often, these sites feature golden alexanders, a plant that visually resembles wild parsnip. Be aware of this look-alike.
- Also check disturbed landscapes that are relatively open. For example, you might try trails through natural areas, pastures, edges of agricultural fields, waste areas, unmaintained gravel pits, and idle lands.
Maps: Special maps (such as EDDMapS, below) let you see where wild parsnip has already been reported.
- Tip: Zoom into your neighborhood to see if wild parsnip has already been reported.
- Tip: Filter the map to view only “positive” reports.
- Tip: Check the date of reports and prioritize recent reports.
- To view the map in a new window, use this link: https://www.eddmaps.org/distribution/viewmap.cfm?sub=6147
EDDMapS: Wild parsnip reports
Phenology
Phenophases for wild parsnip are available on the species profile page by USA-NPN.
- Leaves appear as early as mid-March. Reproductively active plants lose their leaves shortly after fruits mature. Leaves on younger plants persist through the fall until conditions become too cold.
- Flowers appear in about June and can be active through August.
- Fruits appear in about July and persist on the plant through fall, sometimes into winter.
Volunteers collect phenophase data using Nature's Notebook (mobile app, website, or paper datasheets).
Wild parsnip phenophases
The videos and text below show what to look for when assessing phenophases in wild parsnip.
Initial growth
New growth of the plant is visible after a period of no growth (winter or drought), either from above-ground buds with green tips, or new green or white shoots breaking through the soil surface. Growth is considered "initial" on each bud or shoot until the first leaf has fully unfolded. For seedlings, "initial" growth includes the presence of the one or two small, round or elongated leaves (cotyledons) before the first true leaf has unfolded. (Source: USA-NPN)
Leaves
One or more live, fully unfolded leaves are visible on the plant. For seedlings, consider only true leaves and do not count the one or two small, round or elongated leaves (cotyledons) that are found on the stem almost immediately after the seedling germinates. Do not include fully dried or dead leaves. (Source: USA-NPN)
Flowers or flower buds
One or more fresh open or unopened flowers or flower buds are visible on the plant. Include flower buds or inflorescences that are swelling or expanding, but do not include those that are tightly closed and not actively growing (dormant). Also do not include wilted or dried flowers. (Source: USA-NPN)
Open flowers
One or more open, fresh flowers are visible on the plant. Flowers are considered "open" when the reproductive parts (male stamens or female pistils) are visible between or within unfolded or open flower parts (petals, floral tubes or sepals). Do not include wilted or dried flowers. (Source: USA-NPN)
Fruits
One or more fruits are visible on the plant. For Pastinaca sativa, the fruit is flattened and seed-like, with two tiny fruits joined tightly together, and changes from green to yellowish to tan or light brown and splits into two one-seeded segments. (Source: USA-NPN)
Ripe fruits
One or more ripe fruits are visible on the plant. For Pastinaca sativa, a fruit is considered ripe when it has turned tan or light brown. (Source: USA-NPN)
Recent fruit or seed drop
One or more mature fruits or seeds have dropped or been removed from the plant since your last visit. Do not include obviously immature fruits that have dropped before ripening, such as in a heavy rain or wind, or empty fruits that had long ago dropped all of their seeds but remained on the plant. (Source: USA-NPN)