Wild parsnip
Invasive Species Information

Creeping Bellflower - Campanula rapunculoides Biodiversity, Medium Risk Invasive Species

What Is Wild parsnip - (Pastinaca sativa)?

Habitat: Terrestrial
Distribution in Ireland: Naturalised

Status: Common in many areas

Family name: Apiaceae (Carrot family)

Common name/s: Wild Parsnip, Field Parsnip, Common Parsnip

Reproduction:

Wild Parsnip reproduces through seed production:

Seed Dispersal: The seeds are dispersed by wind, water, and human activities, such as mowing and the movement of soil.

Clover broomrape Biodiversity Medium Risk Invasive Species 14

Wild parsnip flowers

Wild Parsnip is a tall, biennial herbaceous plant known for its yellow, umbrella-shaped flower clusters and large, lobed leaves.

Native to Europe and Asia, it has become widespread in many parts of the world, including North America, where it is often considered invasive.

The plant is noted for its potential to cause skin irritation through contact with its sap, which can make management challenging

Wild parsnip leaves

Each plant can produce hundreds to thousands of seeds, which can remain viable in the soil for several years.

Biennial Lifecycle: The plant typically grows as a rosette in its first year and flowers in its second year, after which it dies. This lifecycle allows it to establish a persistent seed bank in suitable habitats.

The plant prefers full sun and grows well in a variety of soil types, from sandy to clay soils, although it favours moist, well-drained conditions.

Managing Wild Parsnip involves controlling its spread and reducing the risks associated with skin contact:

Mechanical Control: Mowing or cutting the plants before they flower can help prevent seed production, though repeated mowing may be necessary to exhaust the plant's energy reserves. Hand-pulling or digging out the taproot can be effective for small infestations, but protective clothing should be worn to avoid skin contact with the sap.
Chemical Control: Herbicides may be used for larger infestations, especially in areas where mechanical control is impractical. Application is most effective on young plants or rosettes before they flower.

Preventative Measures: Monitoring disturbed areas and road verges for early signs of growth and prompt removal of plants can help prevent the establishment of large infestations.

How To Identify Wild parsnip?

Wild parsnip - Pastinaca sativa ID Guide

Leaf: Pinnately compound, with 5-15 leaflets that are ovate to oblong in shape and have coarsely toothed edges
Flower: Yellow, umbrella-shaped flower clusters (umbels), which can be 10-20 cm in diameter
Stem: The stems are hollow, grooved, and branched, with a green to yellowish-green colour
Fruit: Forms flat, oval-shaped seeds that are ribbed and brown when mature. The seeds are 2.5-5 mm long and can be dispersed by wind or water

Root: The plant has a thick, cream-coloured taproot, which resembles the cultivated parsnip used in cooking, although wild parsnip roots are often smaller and more fibrous.

Wild parsnip stand

Wild parsnip seed pods

Wild parsnip seed

Why Is Wild parsnip A Problem?

Wild Parsnip can have several ecological impacts in areas where it becomes established:

Competition with Native Species: Can outcompete native plants, particularly in disturbed habitats, reducing biodiversity.
Alteration of Grassland Structure: Dense stands of Wild Parsnip can dominate open areas, changing the composition of grassland and meadow ecosystems.

Human Health Risk: The plant's sap contains photosensitising chemicals (furanocoumarins) that can cause skin irritation, blistering, and burns when exposed to sunlight, posing a risk to people who come into contact with it.

*Sap/Juices contain Furanocoumarin.

Furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. They are biosynthesized partly through the phenylpropanoid pathway and the mevalonate pathway, which is biosynthesized by a coupling of dimethylallyl pyrophosphate (DMAPP) and 7-hydroxycoumarin (umbelliferone).

Many furanocoumarins are toxic and are produced by plants as a defense mechanism against predators such as insects and mammals. This class of phytochemical is responsible for the phytophotodermatitis seen in exposure to the juices of the wild parsnip and the giant hogweed.

Medication interactions:-

Furanocoumarins have other biological effects. For example, in humans, bergamottin and 6',7'-dihydroxybergamottin are responsible for the "grapefruit juice effect", in which furanocoumarins affect certain P450 liver and gut enzymes, such as the inhibition of CYP3A4 which either activates or deactivates many drugs, leading to higher or lower levels in the bloodstream.

Furanocoumarins have various effects which can specifically increase or decrease (depending on the drug) the blood levels of many pharmaceuticals in ways that can be life-threatening. Approved drugs will include warnings for grapefruit.