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 PA.
, Ailanthus altissima
, grows throughout PA. Another immigrant from China introduced as an ornamental.
, Albizia julibrissin
, has escaped cultivation to invade roadsides and woodland edges in eastern PA.
White mulberry (PDF)
, Morus alba
, 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)
, Buddleja davidii
, has numerous cone-shaped bunches of purple flowers that attract butterflies.
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.
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)
, Rosa multiflora
, this import from Asia has become a noxious weed in PA field, pastures and woodlands.
, Rubus phoenicolasius
, imported from Asia for its raspberry-like fruit and now common on roadsides and in woods and thickets.
Japanese spirae (PDF)
, Spiraea japonica
imported from Japan for its pink flowers. It escapes from cultivation to
forest openings and meadows.
Guelder rose (PDF)
, Viburnum opulus
, a tall
shrub with maple-like leaves imported from Eurasia and escaped to woods fields
Chocolate Vine (PDF)
, Akebia quinata
woody twining vine from Asia that has escaped cultivation
to disturbed woods in southeastern PA.
, a deciduous, woody, perennial vine in the grape family
imported from Asia.
Oriental bittersweet (PDF)
, Celastrus orbiculatus
twining woody vine imported from Asia and rapidly replacing the native
bittersweet in the woods.
, 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 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
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)
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
native to Asia. It is currently found in a few counties in southern PA,
usually alongside invasive stiltgrass.
Cheatgrass and Povery 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)
, Microstegium vimineum
introduced from tropical Asia in packing material and spreading through moist
areas open woods and clearings across southeastern PA and probably
Wavyleaf Basketgrass (PDF)
, Oplismenus undulatifolius
, 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 habtitat for native wildlife.
Common reed (PDF)
, Phragmites australis
very large perennial grass, forms extensive colonies in wetlands. The scattered
native American populations are being replaced by the vigorous European
Golden bamboo (PDF)
, Phyllostachys aurea
, is a
very tall grass with round, hollow stems that spreads rapidly via its
Ravenna grass (PDF)
, Saccharum ravennae
, is also
known as hardy pampas grass. It grows up to 10 feet tall and quickly colonizes
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.
, Sorghum bicolor,
imported from Africa as a forage crop but is now a noxious weed in
, Sorghum halepense
native to the Mediterranean region. It is designated as a noxious weed in
, Aegopodium podagraria
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)
, Anthriscus sylvestris
, 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)
, Carduus nutans
, is also
known as nodding thistle from the way the flowers droop once mature.
Canada thistle (PDF)
, Cirsium arvense
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
brought to U.S. gardens from Europe in the 1800s it now invades
native plant communities in riparian woodlands, open floodplains and stream
, Coronilla varia
sprawling perennial native to southern Europe planted extensively
along highways. It spreads into open, grassland and prairie habitats.
, 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
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
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.
, Hesperis matronalis
introduced from Europe to American gardens, now common
in low woods floodplains and roadside ditches throughout
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.
, Lysimachia nummularia
by many common names and was introduced into the U.S. from Europe as an
Purple loosestrife (PDF)
, Lythrum salicaria
European perennial with a woody base that has escaped gardens and destroyed
large areas of waterfowl habitat by dominating wetlands and excluding all other
, Ornithogalum nutans
, garden bulbs from Europe that escape to infest lawns and
Japanese pachysandra (PDF)
, Pachysandra terminalis
an evergreen perennial groundcover that can spread from cultivation into
natural areas if left uncontrolled.
Wild parsnip (PDF)
, Pastinaca sativa
European import now a widespread and abundant weed of roadsides throughout PA.
Beefsteak plant (PDF)
, Perilla frutescens
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)
and F. sachalinensis
, are extremely difficult weeds to
control. Imported from Japan they dominate stream and river banks
Carolina fanwort (PDF)
, Cabomba caroliniana
, is a
submerged, rooted plant native to the southeastern U.S. and sold for aquariums.
, 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 verticillata
, is a
submerged aquatic plant that resembles several other aquatic plants, making ID
Floating Primrose-willow (PDF)
peploides ssp. glabrescens,
is indigenous to slow-moving waters
of the southeastern U.S. now found in across southern PA.
Curly pondweed (PDF)
, Potamogeton crispus
aggressive European weed common in lakes, ponds and streams.