Invasive Plant Fact Sheets
For help in identification of invasive plants, treatment, and protection suggestions for your property, explore the DCNR fact sheets below.
DCNR has deemed these trees, shrubs, vines, herbs, and aquatic plants to be invasive on state lands. The species listed are managed by DCNR staff.
Amur maple (PDF)
, is a small ornamental tree that spreads by numerous winged seeds.
Norway maple (PDF)
, a common street and lawn tree that frequently escapes cultivation.
Sycamore maple (PDF)
, Acer pseudoplatanus
, a tall Eurasian tree invading urban and suburban woods in southern PA.
, grows throughout PA. Another immigrant from China introduced as an ornamental.
, has escaped cultivation to invade roadsides and woodland edges in eastern PA.
White mulberry (PDF)
, is a fast-growing species that will hybridize with our native red mulberry, Morus rubra.
Cork tree (PDF)
Phellodendron amurense, P. japonicum, P. lavallei
, these Asian trees are problematic in urban and natural areas in southeastern PA.
Bee-bee tree (PDF)
Tetra dium daniellii
, is an uncommon landscape tree that is slowly spreading in south-central and southeastern PA.
Butterfly bush (PDF)
, has numerous cone-shaped bunches of purple flowers that attract butterflies.
Winged euonymus or Burning-bush (PDF)
, a shrub from China and Japan imported for its bright purple-red fall color and frequently found along streams and in woods mostly in southern PA.
species imported from Europe and Asia are aggressive, thicket forming shrubs.
, is a deciduous shrub with clusters of small black fruits and white four-petaled flowers.
Multiflora Rose (PDF)
, this import from Asia has become a noxious weed in PA field, pastures and woodlands.
, imported from Asia for its raspberry-like fruit and now common on roadsides and in woods and thickets.
Japanese spiraea (PDF)
, was imported from Japan for its pink flowers. It escapes from cultivation to forest openings and meadows.
Guelder rose (PDF)
, a tall shrub with maple-like leaves imported from Eurasia and escaped to woods fields and roadsides.
Chocolate Vine (PDF)
, a woody twining vine from Asia that has escaped cultivation to disturbed woods in southeastern PA.
, Ampelopsis brevipedunculata
, a deciduous, woody, perennial vine in the grape family imported from Asia.
Oriental bittersweet (PDF)
, a twining woody vine imported from Asia and rapidly replacing the native bittersweet in the woods.
, is an evergreen woody vine that aggressively invades forest edges and openings.
English ivy (PDF)
, is a common evergreen climbing vine in the landscape that can smother native vegetation.
Japanese honeysuckle (PDF)
, a common ornamental vine from Asia now an abundant weed in roadside thickets, woods, and fields across southern PA.
Mile-a-minute weed (PDF)
, a slender annual vine with reflexed prickles was accidentally introduced from Asia with nursery stock and now a noxious weed in PA.
, Pueraria lobata
, a vigorous half-woody vine introduced from Asia for ornament, forage and erosion control and now an uncommon but officially noxious weed in southeastern PA.
Chinese and Japanese wisteria (PDF)
, are long-lived woody vines with bright purple flowers that can out-compete and smother native vegetation.
Small carpetgrass (PDF)
, is native to Asia. It is currently found in a few counties in southern PA, usually alongside invasive stiltgrass.
Cheatgrass and Poverty brome (PDF)
, Bromus tectorum and B. sterilis, accidentally introduced from Europe in ballast soil or impure wheat seed shipments. A serious agricultural weed in the Midwest and western states.
Japanese stiltgrass (PDF)
, introduced from tropical Asia in packing material and spreading through moist areas open woods and clearings across southeastern PA and probably elsewhere .
Reed canary grass (PDF)
, Phalaris arundinacea
, forms dense monocultures in wet habitats that disrupt waterways and degrade habtitat for native wildlife.
Common reed (PDF)
, a very large perennial grass, forms extensive colonies in wetlands. The scattered native American populations are being replaced by the vigorous European subspecies.
Ravenna grass (PDF)
, is also known as hardy pampas grass. It grows up to 10 feet tall and quickly colonizes wet habitats.
Tall fescue (PDF)
, is a very common cool season perennial grass that adapts to a variety of conditions and crowds out native vegetation.
Shattercane and Johnsongrass (PDF)
and Sorghum halepense
was imported from Africa and the Mediterranean region as a forage crop but is now a noxious weed in Pennsylvania.
, imported from Eurasia and frequently found in fields, thickets, woods and roadsides throughout PA.
, Alliaria petiolata
, a weed of shady moist spots in suburban gardens, woods and floodplains throughout PA; introduced from Europe.
Wild chervil (PDF)
, is a member of the carrot family that competes with native plants and carries a virus that can infect some vegetable crops.
Musk thistle (PDF)
, is also known as nodding thistle from the way the flowers droop once mature.
Canada thistle (PDF)
, imported from Eurasia (not Canada) now common and noxious weed in fields pastures and roadsides throughout PA.
Bull thistle (PDF)
, is a large-flowered thistle with long spines and abundant seeds.
Poison hemlock (PDF)
, was brought to U.S. gardens from Europe in the 1800s it now invades native plant communities in riparian woodlands, open floodplains and stream banks.
, a sprawling perennial native to southern Europe planted extensively along highways. It spreads into open, grassland and prairie habitats.
, is a state noxious weed that is highly toxic and frequently found in cultivated fields and other disturbed sites.
Goats rue (PDF)
, is a state and federal noxious weed that is very poisonous to livestock.
Orange day-lily (PDF)
, is a very hard perennial that grows in abundance along roadsides and old home sites.
Giant hogweed (PDF)
, 15 feet tall member of the carrot family introduced from Eurasia. Its sap can cause blisters so it is listed as a federal and PA noxious weed.
, introduced from Europe to American gardens, now common in low woods floodplains and roadside ditches throughout PA.
Yellow flag iris (PDF)
, is a showy ornamental plant commonly found in wetlands, along pond edges, and other wet areas where it can dominate.
, goes by many common names and was introduced into the U.S. from Europe as an ornamental groundcover.
Purple loosestrife (PDF)
, a European perennial with a woody base that has escaped gardens and destroyed large areas of waterfowl habitat by dominating wetlands and excluding all other plant life.
, garden bulbs from Europe that escape to infest lawns and roadsides.
Japanese pachysandra (PDF)
, is an evergreen perennial groundcover that can spread from cultivation into natural areas if left uncontrolled.
Wild parsnip (PDF)
, a European import now a widespread and abundant weed of roadsides throughout PA.
Beefsteak plant (PDF)
, a member of the mint family introduced from India now occasionally found in moist shaded roadsides and woods.
Bristled knotweed (PDF)
, is an annual plant from Asia that can dominate wet, disturbed habitats. , Persicaria longiseta, is an annual plant from Asia that can dominate wet, disturbed habitats.
Japanese and Giant knotweed (PDF)
, Fallopia japonica
, are extremely difficult weeds to control. Imported from Japan they dominate stream and river banks throughout PA.
Carolina fanwort (PDF)
, is a submerged, rooted plant native to the southeastern U.S. and sold for aquariums.
, is a microscopic alga called a diatom. It can form dense mats that smother stream beds and native vegetation.
Brazilian water-weed (PDF)
, is a popular aquarium plant that can grow vigorously and choke out native vegetation once it reaches ponds, lakes and other waterbodies.
, is a submerged aquatic plant that resembles several other aquatic plants, making ID difficult.
Floating Primrose-willow (PDF)
Ludwigia peploides ssp.
is indigenous to slow-moving waters of the southeastern U.S. now found in across southern PA.
Curly pondweed (PDF)
, Potamogeton crispus
, an aggressive European weed common in lakes, ponds and streams.