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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.

Trees

  • 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 PA.
  • European black alder (PDF), Alnus glutinosa, is often found along streams and other wet areas.
  • Tree-of-heaven (PDF), Ailanthus altissima, grows throughout PA. Another immigrant from China introduced as an ornamental.
  • Mimosa (PDF), Albizia julibrissin, has escaped cultivation to invade roadsides and woodland edges in eastern PA.
  • Japanese angelica tree (PDF, Aralia elata, has sharp spines on the trunk and resembles our native devil's waking 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 PA by winged seeds.
  • Cork tree (PDF), Phellodendron amurense, P. japonicum, P.  lavallei, these Asian trees are problematic in urban and natural areas in southeastern PA.
  • Callery or Bradford pear (PDF), Pyrus calleryana, has established populations in fields and hedgerows 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.
  • Siberian elm (PDF), U lm us pumila, a fast growing tree reaching 50-70 feet high.

Shrubs

  • European and Japanese barberries (PDF) , Berbe r is vulgaris and B. thunbergii, form dense thickets in woodlands, wetlands and meadows.
  • Butterfly bush (PDF) , Budd le ja davidii, has numerous cone-shaped bunches of purple flowers that attract butterflies.
  • Russian olive and Autumn olive (PDF) , Elaeag n us angustifolia and E. umbellata, imported from Asia, have become serious weeds in southern PA pastures and other open ground.
  • Winged euonymus or Burning-bush (PDF) , Euonymus alatus, 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.
  • Chinese and Shrubby bushclovers (PDF) , Lesp ed eza cuneata and L. bicolor, are semi-woody shrubs that readily invade open and disturbed habitats.
  • Privets (PDF ) , Lig ust rum species imported from Europe and Asia are aggressive, thicket forming shrubs.
  • Shrub honeysuckles (PDF) , five Lonicera species that rapidly invade and dominate field edges and pastures.
  • Common buckthorn (PDF) and Glossy buckthorn (PDF ) , R ham nus cathartica and R. frangula (syn. Frangula alnus). Small trees or shrubs to 20' high with yellow sapwood and pink to orange heartwood.
  • J e t bead (P DF ) , R ho d o t yp o s s ca nden s , is a deciduous shrub with clusters of small black fruits and white four-petaled flower s.
  • M ultiflora rose (PDF) , Rosa multiflora, this import from Asia has become a noxious weed in PA field, pastures and woodlan ds.
  • W ineberry (PDF) , R ubus pho en i colasi us, imported from Asia for its raspberry-like fruit and now common on roadsides and in woods and thickets.
  • Japanese spirae (PDF) , Spiraea japonica, was imported from Japan for its pink flowers. It escapes from cultivation to forest openings and mead ow s.
  • Doublefile viburnum (PD F) , Viburn u m plicatum, Linden viburnum (PDF) , V . d ila taum,  and S iebo ld vi burnum ( PDF) , V. sieboldii, a re Asian shrubs with abundant fruits that are spread by bi rds.
  • Guelder rose (PDF) , V i b urn um o pulus, a tall shrub with maple-like leaves imported from Eurasia and escaped to woods fields and roadsides.

Vines

  • Five-leaf akebia (PDF) , A keb i a quinata, a woody twining vine from Asia that has escaped cultivation to disturbed woods in southeastern PA.
  • 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 woods and fencer ow s. 
  • Wintercreeper (PDF) , Euony m us for tunei , 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 ) , Humulu s 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 PA.
  • 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 PA.
  • Kudzu (PDF) , Pue r aria 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.
  • Common and Bigleaf periwinkle (PD F) , Vin c a minor and V. major, are evergreen, ornamental groundcovers that can form thick mats, even under dense tree canopy.
  • Black and Pale swallow-wort (PDF) , V incetoxicum 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.

Grasses

  • Small carpetgrass (PDF) , An t h r a xon his p idus, is native to Asia.  It is currently found in a few counties in southern PA, usually alongside invasive sti ltgrass.
  • Cheatgrass and Povery br ome (PD F ) , B r omus t e ctoru m, 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) , Mic r o stegium v imineum, introduced from tropical Asia in packing material and spreading through moist areas open woods and clearings across southeastern PA and probably elsewhere .
  • Chinese silvergrass (PDF) , M is canthus sinensis, is a tall bunched grass that spreads through vigorous roots and rhizom es.
  • Wavyleaf basketgrass (P DF) , Opl i s menus undu latifolius, is a fast-growing, creeping grass not yet in PA but found across the border in Maryland.
  • Reed canary grass (PDF) , Phalaris arundinacea, forms dense monocultures in wet habitats that disrupt waterways and degrade habitat for native wildlife.
  • Common reed (PDF) , Phragm ites 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 bamboo (PDF) , Phyllosta chys 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) , Sacch arum ravennae, is also known as hardy pampas grass. It grows up to 10 feet tall and quickly colonizes wet habitats.
  • Tall fescue (PDF) , Schedon orus arundinaceus, is a very common cool season perennial grass that adapts to a variety of conditions and crowds out native vegetation.
  • Shattercan (PDF) , Sorg hum bicolor was imported from Africa as a forage crop but is now a noxious weed in Pennsylvania.
  • Johnsongrass (PDF) , So r g hum h ale pen se, is native to the Mediterranean region. It is designated as a noxious weed in Pennsylvania.

Herbs

  • Goutweed (PDF) , Ae gopodium podagraria, imported from Eurasia and frequently found in fields, thickets, woods and roadsides throughout PA.
  • Garlic-mustard (PDF) , Alliaria petiolata, a weed of shady moist spots in suburban gardens, woods and floodplains throughout PA; introduced from Europe.  
  • Wild chervil (PDF) , An thriscus 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) , C a r damine 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. stoebe micranthos, 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 PA.
  • Bull thistle (PDF) , Cirsium vulgare, is a large-flowered thistle with long spines and abundant seeds.
  • Poison hemlock (PDF) , Conium maculatum, 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.
  • 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) , Epi lobium 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 day-lily (PDF) , Hemorocallis fulva, is a very hard perennial that grows in abundance along roadsides and old home sites.
  • Giant hogweed (PDF) , Heracleum mantegazzianum, 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.
  • Dame's-rocket (PDF) , Hesperis matronalis, introduced from Europe to American gardens, now common in low woods floodplains and roadside ditches throughout PA.  
  • 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 U.S. 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 PA.
  • 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. , 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 PA.
  • 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 U.S. and sold for aquariums.
  • Didymo (PDF) , Di dymoshenia 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) , Hy dr illa verticillata, is a submerged aquatic plant that resembles several other aquatic plants, making ID difficult.
  • Floating Primrose-willow (PDF) , Ludwigia peploides ssp. glabrescens is indigenous to slow-moving waters of the southeastern U.S. now found in across southern PA.  
  • Parrot feather watermilfoil (PDF) , Myriophyllum aquaticum, is an aquarium plant native to South America that can form dense mats in PA lakes and ponds.
  • Eurasian Water-milfoil (PDF) , Myriophyllum spicatum, a common an abundant Eurasian invader of lakes and rivers throughout PA.
  • Curly pondweed (PDF) , Potamogeton crispus, an aggressive European weed common in lakes, ponds and streams.
  • Water-chestnut (PDF) , Trapa natans, a locally abundant Eurasian invader of ponds and lakes.
  • Narrow-leaved cattail (PDF) , Typha angustifolia, is from Europe and difficult to visually distinguish from our native cattail.
  • Hybrid cattail (PDF) , Typha x glauca, a cross between narrow-leaved cattail and native common.