Harmful Plants

The plants below can cause rashes or skin irritation. Familiarize yourself with how to identify these harmful plants and keep an eye out for them when enjoying the outdoors.

Poison Ivy

Poison ivy grows as a vine or small shrub that can trail along the ground or climb 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. The plant may have greenish-white flowers and whitish-yellow berries. 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. Poison ivy is often found growing in young woodlands, thickets, path edges, sand dunes, walls and roadways. More information on poison ivy.

Poison Sumac

This plant can appear as a woody shrub or small tree and grows up to 20 feet tall. Each leaf has clusters of 7-13 smooth-edged leaflets. Its leaves are orange in spring, green in summer, and yellow, orange, or red in fall. Poison sumac may have yellow-greenish flowers and whitish green fruits that hang in loose clusters, and can be found growing 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 is very large, erect biennial or perennial. The plant has white flowers that 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, can be 8-14 feet tall, and have purple blotches and coarse hairs. Leaves can be 5 feet across and are lobed and deeply incised. Giant hogweed is usually found growing in rich, moist soils in open fields, wooded areas, tree lines, roadsides, ditches and along streams and rivers. Its 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

This large plant grows 3-10 feet tall. Leaves are 12"-18", rough and hairy, and 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. The plant has white or cream colored flowers that bloom in mid-summer. These flowers have 5 petals of different sizes and are arranged in broad, flat-topped clusters at the top of short stalks. Cow parsnip grows in a variety of habitats including woodlands, forest openings, grasslands, stream and river edges and along roadsides. Its 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 typically grows 2-5 feet tall and is found along roadsides, in pastures, and in fields. Its 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. The plant's stem is hollow and deeply grooved. Wild parsnip has small, 5-petaled, yellow flowers that are arranged in a flat-topped broad umbel 2-6 inches across and appear June-September. The flowers produce a round, smooth, straw-colored seed pod that is approximately 0.25 inches in size. Sap in all parts of the plant 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 a perennial, erect herb that can be identified by its stinging hairs, opposite heart-shaped leaves, and small greenish flowers. The stinging hairs on stems and leaves produce an intense burning and itching sensation that can last up to 30 minutes. The plant is most often found in forests or at the edges of woods and streams. 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 on your property, or you see it in the community, report it to [email protected] or call DEC at 845-256-311. If emailing, please include photos if possible to help with identification.
  • If you think you have wild parsnip on your property, or you see it in the community, report it to iMapInvasives (leaves DEC website).
  • Do not touch, cut, or collect parts of these plants, even for identification purposes.