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Harmful Plants

When you are enjoying the outdoors, keep an eye out for these harmful plants. They can cause rashes or skin irritation.

Poison Ivy

Poison Ivy

Can grow as a vine or small shrub trailing along the ground or climbing on low plants, trees and poles. Each leaf has three glossy leaflets, with smooth or toothed edges. Leaves are reddish in spring, green in summer, and yellow, orange, or red in fall. May have greenish-white flowers and whitish-yellow berries. Often found in young woodlands, thickets, path edges, sand dunes, walls and roadways. Every part of the plant contains an oil that inflames skin and results in painfully itchy blisters and rashes. Inhalation of smoke from burning leaves and vines is extremely hazardous. More information on poison ivy.

Poison Sumac

Poison Sumac

A woody shrub or small tree growing up to 20 feet tall. Each leaf has clusters of seven to 13 smooth-edged leaflets. Leaves are orange in spring, green in summer, and yellow, orange, or red in fall. May have yellow-greenish flowers and whitish green fruits hang in loose clusters. Grows exclusively in very wet or flooded soils, usually in swamps and peat bogs. Every part of the plant contains an oil that inflames skin and results in painfully itchy blisters and rashes. Inhalation of smoke from burning leaves and vines is extremely hazardous. More information on poison sumac.

Giant Hogweed

Giant Hogweed

A very large, erect biennial or perennial. Small white flowers appear in late summer, forming a large, flat-topped umbel up to 2.5 feet across. Hollow, rigid stems grow 2-4 inches in diameter and 8-14 feet tall, and have purple blotches and coarse hairs. Leaves can be 5 feet across, are lobed and deeply incised. Grows in rich, moist soils in open fields, wooded areas, tree lines, roadsides, ditches and along streams and rivers. Sap contains a phototoxin that reacts with ultraviolet light to cause skin irritation ranging from a mild rash to severe blistering. More information on giant hogweed.

Cow Parsnip

cow parsnip

A large plant that grows from 3-10 feet tall. Leaves are 12"-18" and rough and hairy. Leaves are divided into 3 segments, with coarsely toothed leaflets and a broad wing at the base of each leaf stalk. Stems are rough, hairy, hollow and grooved. It has white or cream colored flowers with a sweet fragrance. Flowers have 5 petals of different sizes and are arranged in broad, flat-topped clusters at the top of short stalks. Blooms in mid-summer. Grows in a variety of habitats including woodlands, forest openings, grasslands, stream and river edges and along roadsides. Sap contains a phototoxin that reacts with ultraviolet light to cause skin irritation ranging from a mild rash to severe blistering. More information on cow parsnip.

Wild Parsnip

wild parsnip

Grows along roadsides, in pastures, and in fields. A large plant that stands erect at 2-5 feet tall. Leaves are alternate, pinnately compound, branched, and have saw-toothed edges. Each leaf has 5-15 ovate to oblong leaflets with variable toothed edges and deep lobes. Stems are hollow and deeply grooved. It has small, 5-petaled, yellow flowers that are arranged in a flat-topped broad umbel 2-6 inches across; flowers June-September. The flowers produce a round, smooth, straw-colored seed pod that is approximately 0.25 inches in size. Wild parsnip has a long, cone-shaped fleshy thick taproot. Sap contains a phototoxin that reacts with ultraviolet light to cause skin irritation ranging from a mild rash to severe blistering. More information wild parsnip.

Stinging Nettle

stinging nettle

Is found in forests and natural areas at the edges of woods and streams. Perennial, erect herb with stinging hairs; opposite heart-shaped leaves, small greenish flowers. The stinging hairs on stems and leaves produce an intense burning and itching sensation that can last up to thirty minutes. More information on stinging nettle.

To keep yourself safe follow these tips:

  • Learn how to identify giant hogweed, wild parsnip, cow parsnip, poison ivy, poison sumac and stinging nettle.
  • Stay on the trails and away from areas known to have these plants.
  • Carefully wash any sap from clothing, equipment and pets.
  • If you think you have Giant Hogweed or Wild Parsnip on your property, or you see it in the community, report it to ghogweed@dec.ny.gov, 845-256-3111 or iMapInvasives.
  • Do not touch, cut, or collect parts of these plants, even for identification purposes.
  • Photographs will help with identification.