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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), Acer ginnala, is a small ornamental tree that spreads by numerous winged seeds.
  • Norway maple (PDF), Acer platanoides, 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 Pennsylvania.
  • European black alder (PDF), Alnus glutinosa, is often found along streams and other wet areas.
  • Tree-of-heaven (PDF), Ailanthus altissima, grows throughout Pennsylvania. Another immigrant from China introduced as an ornamental.
  • Mimosa (PDF), Albizia julibrissin, has escaped cultivation to invade roadsides and woodland edges in eastern Pennsylvania.
  • Japanese angelica tree (PDF), Aralia elata, has sharp spines on the trunk and resembles our native devils walking stick.
  • Paper mulberry (PDF), Broussonetia papyfera, is a common, small ornamental tree from Asia.
  • White mulberry (PDF), Morus alba, is a fast-growing species that will hybridize with our native red mulberry, Morus rubra.
  • Princess-tree, empress-tree (PDF), Paulownia tomentosa, imported from China this purple-flowered tree has spread across southern Pennsylvania by winged seeds.
  • Cork tree (PDF), Phellodendron amurense, P. japonicum, P. lavallei, these Asian trees are problematic in urban and natural areas in southeastern Pennsylvania.
  • Callery or bradford pear (PDF), Pyrus calleryana, has established populations in fields and hedgerows in southeastern Pennsylvania.
  • Bee-bee tree (PDF), Tetra dium daniellii, is an uncommon landscape tree that is slowly spreading in southcentral and southeastern Pennsylvania.
  • Siberian elm (PDF), Ulmus pumila, a fast-growing tree reaching 50-70 feet high.



  • Chocolate vine (PDF), Akebia quinata, a woody twining vine from Asia that has escaped cultivation to disturbed woods in southeastern Pennsylvania.
  • Porcelain berry (PDF), Ampelopsis brevipedunculata, a deciduous, woody, perennial vine in the grape family imported from Asia.
  • Oriental bittersweet (PDF), Celastrus orbiculatus, a twining woody vine imported from Asia and rapidly replacing the native bittersweet in the woods.
  • Winter creeper (PDF), Euonymus fortunei, is an evergreen woody vine that aggressively invades forest edges and openings.
  • English ivy (PDF), Hedera helix, is a common evergreen climbing vine in the landscape that can smother native vegetation.
  • Japanese hops (PDF), Humulus japonicus, is a prickly vine that invades moist, sunny areas.
  • Japanese honeysuckle (PDF), Lonicera japonica, a common ornamental vine from Asia now an abundant weed in roadside thickets, woods, and fields across southern Pennsylvania.
  • Mile-a-minute weed (PDF), Persicaria perfoliata, a slender annual vine with reflexed prickles was accidentally introduced from Asia with nursery stock and now a noxious weed in Pennsylvania.
  • Kudzu (PDF), 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 Pennsylvania.
  • Common and bigleaf periwinkle (PDF), Vinca minor and V. major, are evergreen, ornamental groundcovers that can form thick mats, even under dense tree canopy.
  • Black and pale swallow-wort (PDF), Vincetoxicum nigrum and V. rossicum, are twining vines that can dominate old fields and poison livestock.
  • Chinese and Japanese wisteria (PDF), Wisteria sinensis and W. floribunda, are long-lived woody vines with bright purple flowers that can out-compete and smother native vegetation.


  • Small carpetgrass (PDF), Anthraxon hispidus, is native to Asia. It is currently found in a few counties in southern Pennsylvania, 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.
  • Common velvet grass (PDF), Holcus lanatus, introduced as early as the 17th century in imported pasture seed.
  • Japanese stiltgrass (PDF), Microstegium vimineum, introduced from tropical Asia in packing material and spreading through moist areas open woods and clearings across southeastern Pennsylvania and probably elsewhere.
  • Chinese silvergrass (PDF), Miscanthus sinensis, is a tall bunched grass that spreads through vigorous roots and rhizomes.
  • Wavyleaf basketgrass (PDF), Oplismenus undulatifolius, is a fast-growing, creeping grass.
  • Reed canary grass (PDF), Phalaris arundinacea, forms dense monocultures in wet habitats that disrupt waterways and degrade habtitat for native wildlife.
  • Common reed (PDF), Phragmites australis, a very large perennial grass, forms extensive colonies in wetlands. The scattered native American populations are being replaced by the vigorous European subspecies.
  • Golden, yellow groove, and giant timber bamboo (PDF), Phyllostachys aurea, is a very tall grass with round, hollow stems that spreads rapidly via its underground rhizomes.
  • Rough bluegrass (PDF), Poa trivialis, is a non-descript grass that out-competes native grasses.
  • Ravenna grass (PDF), Saccharum ravennae, is also known as hardy pampas grass. It grows up to 10-feet tall and quickly colonizes wet habitats.
  • Tall fescue (PDF), Schedonorus arundinaceus, is a very common cool season perennial grass that adapts to a variety of conditions and crowds out native vegetation.
  • Shattercane and johnsongrass (PDF), Sorghum bicolor, and Sorghum halepense was imported from Africa and the Mediterranean region as a forage crop but is now a noxious weed in Pennsylvania.


  • Goutweed (PDF), Aegopodium podagraria, imported from Eurasia and frequently found in fields, thickets, woods, and roadsides throughout Pennsylvania.
  • Garlic mustard (PDF), Alliaria petiolata, a weed of shady moist spots in suburban gardens, woods, and floodplains throughout Pennsylvania; introduced from Europe.
  • Wild chervil (PDF), Anthriscus sylvestris, is a member of the carrot family that competes with native plants and carries a virus that can infect some vegetable crops.
  • Narrowleaf bittercress (PDF), Cardamine impatiens, is a member of the mustard family native to Europe.
  • Musk thistle (PDF), Carduus nutans, is also known as nodding thistle from the way the flowers droop once mature.
  • Black, brown, and spotted knapweeds (PDF), Centaurea nigra, C. jacea, C. stoebemicranthos, have pink to purple flowers that resemble small pineapples.
  • Greater celandine (PDF), Chelidonium majus, is a four-petaled yellow flower from Europe that is poisonous.
  • Canada thistle (PDF), Cirsium arvense, imported from Eurasia (not Canada) now common and noxious weed in fields pastures and roadsides throughout Pennsylvania.
  • Bull thistle (PDF), Cirsium vulgare, is a large-flowered thistle with long spines and abundant seeds.
  • Spiny plumeless thistle (PDF), Carduus acanthoides, is a prickly, biennial plant that invades open areas and grasslands.
  • Poison hemlock (PDF), Conium maculatum, was brought to United States gardens from Europe in the 1800s and now invades native plant communities in riparian woodlands, open floodplains, and stream banks.
  • Crown-vetch (PDF), Coronilla varia, a sprawling perennial native to southern Europe planted extensively along highways. It spreads into open, grassland and prairie habitats.
  • Jimsonweed (PDF), Datura stramonium, is a state noxious weed that is highly toxic and frequently found in cultivated fields and other disturbed sites.
  • Smallflower and hairy willow herb (PDF), Epilobium parviflorum and E.hirsutum are ornamental perennials with showy, rose-colored flowers that can quickly form dense stands.
  • Goats rue (PDF), Galega officinalis, is a state and federal noxious weed that is very poisonous to livestock.
  • Orange daylily (PDF), Hemorocallis fulva, is a very hard perennial that grows in abundance along roadsides and old home sites.
  • Giant hogweed (PDF), Heracleum mantegazzianum, 15-foot tall member of the carrot family introduced from Eurasia. Its sap can cause blisters so it is listed as a federal and Pennsylvania noxious weed.
  • Dame’s-rocket (PDF), Hesperis matronalis, introduced from Europe to American gardens, now common in low woods floodplains and roadside ditches throughout Pennsylvania.
  • Yellow flag iris (PDF), Iris pseudacorus, is a showy ornamental plant commonly found in wetlands, along pond edges, and other wet areas where it can dominate.
  • Moneywort (PDF), Lysimachia nummularia, goes by many common names and was introduced into the United States from Europe as an ornamental groundcover.
  • Purple loosestrife (PDF), Lythrum salicaria, 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.
  • Star-of-Bethlehem (PDF), Ornithogalum nutans and O. umbellatum, garden bulbs from Europe that escape to infest lawns and roadsides.
  • Japanese pachysandra (PDF), Pachysandra terminalis, is an evergreen perennial groundcover that can spread from cultivation into natural areas if left uncontrolled.
  • Wild parsnip (PDF), Pastinaca sativa, a European import now a widespread and abundant weed of roadsides throughout Pennsylvania.
  • Beefsteak plant (PDF), Perilla frutescens, a member of the mint family introduced from India now occasionally found in moist shaded roadsides and woods.
  • Bristled knotweed (PDF), Persicaria longiseta, is an annual plant from Asia that can dominate wet, disturbed habitats.
  • Japanese and giant knotweed (PDF), Fallopia japonica and F. sachalinensis, are extremely difficult weeds to control. Imported from Japan, they dominate stream and river banks throughout Pennsylvania.
  • Lesser celandine (PDF), Ranunculus ficaria, an aggressive weed in wetlands imported from Eurasia.

Aquatic Plants

  • Carolina fanwort (PDF), Cabomba caroliniana, is a submerged, rooted plant native to the southeastern United States and sold for aquariums.
  • Didymo (PDF), Didymoshenia geminate, is a microscopic alga called a diatom. It can form dense mats that smother stream beds and native vegetation.
  • Brazilian water-weed (PDF), Egeria densa, is a popular aquarium plant that can grow vigorously and choke out native vegetation once it reaches ponds, lakes and other waterbodies.
  • Hydrilla (PDF), Hydrilla verticillata, is a submerged aquatic plant that resembles several other aquatic plants, making identification difficult.
  • Starry stonewort (PDF), Nitellopsis obtusa, is a freshwater micro-algae native to Europe and Asia.
  • Floating primrose-willow (PDF), Ludwigia peploides ssp. glabrescens, is indigenous to slow-moving waters of the southeastern United States and is now found across southern Pennsylvania.
  • Parrot feather watermilfoil (PDF), Myriophyllum aquaticum, is an aquarium plant native to South America that can form dense mats in Pennsylvania lakes and ponds.
  • Eurasian water-milfoil (PDF), Myriophyllum spicatum, a common an abundant Eurasian invader of lakes and rivers throughout Pennsylvania.
  • Curly pondweed (PDF), Potamogeton crispus, an aggressive European weed common in lakes, ponds, and streams.
  • Water chestnut (PDF), Trapanatans, a locally abundant Eurasian invader of ponds and lakes.
  • Narrow-leaved cattail (PDF), Typhaangustifolia, is from Europe and difficult to visually distinguish from our native cattail.
  • Hybrid cattail (PDF), Typhaxglauca, a cross between narrow-leaved cattail and native common.