Ezina · A field manual for plant care · United StatesVol. I · Ed. 2027 · Proof copy

Pennsylvania invasive plants

Pennsylvania (PA) regulates 57 invasive plants under 3 Pa.C.S. 1501-1562 (Act 46 of 2017). Pennsylvania's list is a trade restriction, which governs what may be sold, propagated, or moved within the state — in plain terms, which plants are illegal to sell here.

Pennsylvania invasive species list

Pennsylvania restricts 57 plants, including Purple Loosestrife, Canada Thistle and Waterthyme. Plants marked Prohibited may not be sold, propagated, or moved within Pennsylvania. 49 of the 57 are also flagged invasive by GRIIS, which is an ecological finding rather than a ruling by Pennsylvania. Checked against 3 Pa.C.S. 1501-1562 (Act 46 of 2017) on July 20, 2026.

Amur Honeysuckle – Lonicera maackii IntroducedInvasive

Amur Honeysuckle (Lonicera maackii)
Photo by Herman, D.E., et al / Public domain / ND State Soil Conservation Committee / via USDA PLANTS

Invasive in the US, and recorded in 11 of Pennsylvania’s 67 counties. Pennsylvania lists Amur Honeysuckle under “Class B.”

Animated Oat – Avena sterilis Not recorded hereInvasive

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Animated Oat under “Class A.”

Asiatic Tearthumb – Polygonum perfoliatum IntroducedInvasive

Asiatic Tearthumb (Polygonum perfoliatum)
Photo by Dalgial / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 9 of Pennsylvania’s 67 counties. Pennsylvania lists Asiatic Tearthumb under “Class B.”

Basketgrass – Oplismenus hirtellus Not recorded hereProhibited

Basketgrass (Oplismenus hirtellus)
Photo by Robert H. Mohlenbrock. USDA SCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Recorded in no Pennsylvania county. Pennsylvania lists Basketgrass under “Class A.”

Blood Grass – Imperata cylindrica Not recorded hereInvasive

Blood Grass (Imperata cylindrica)
Photo by No machine-readable author provided. Keisotyo assumed (based on copyright claims). / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Blood Grass under “Class A.”

Bohemian Knotweed – Polygonum x bohemicum Not recorded hereProhibited

Recorded in no Pennsylvania county. Pennsylvania lists Bohemian Knotweed under “Class B.”

Border Privet – Ligustrum obtusifolium IntroducedInvasive

Border Privet (Ligustrum obtusifolium)
Photo by Mason Brock ( Masebrock ) / Public domain / Wikimedia Commons

Invasive in the US, and recorded in 28 of Pennsylvania’s 67 counties. Pennsylvania lists Border Privet under “Class B.”

Brazilian Waterweed – Egeria densa IntroducedInvasive

Brazilian Waterweed (Egeria densa)
Photo by Lara Gudmundsdottir / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in 4 of Pennsylvania’s 67 counties. Pennsylvania lists Brazilian Waterweed under “Class A.”

Bull Thistle – Cirsium vulgare IntroducedInvasive

Bull Thistle (Cirsium vulgare)
Photo by Patrick J. Alexander / Public domain / via USDA PLANTS

Invasive in the US, and recorded in 64 of Pennsylvania’s 67 counties. Pennsylvania lists Bull Thistle under “Class B.”

Burning Bush – Euonymus alatus IntroducedInvasive

Burning Bush (Euonymus alatus)
Photo by Chris Barton/Gif absarnt / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 14 of Pennsylvania’s 67 counties. Pennsylvania lists Burning Bush under “Class B.”

Callery Pear – Pyrus calleryana IntroducedInvasive

Callery Pear (Pyrus calleryana)
Photo by Bruce Marlin / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 2 of Pennsylvania’s 67 counties. Pennsylvania lists Callery Pear under “Class B.”

Canada Thistle – Cirsium arvense IntroducedInvasive

Canada Thistle (Cirsium arvense)
Photo by Richard Bartz, Munich aka Makro Freak / CC BY-SA 2.5 / Wikimedia Commons

Invasive in the US, and recorded in 61 of Pennsylvania’s 67 counties. Pennsylvania lists Canada Thistle under “Class B.”

Carelessweed – Amaranthus palmeri NativeProhibited

Carelessweed (Amaranthus palmeri)
Photo by Steve Hurst / Public domain / ARS Systematic Botany and Mycology Laboratory / via USDA PLANTS

Recorded in 4 of Pennsylvania’s 67 counties. Pennsylvania lists Carelessweed under “Class A.”

Common Buckthorn – Rhamnus cathartica IntroducedInvasive

Common Buckthorn (Rhamnus cathartica)
Photo by Köhler, F. E. (Franz Eugen) / Public domain / Wikimedia Commons

Invasive in the US, and recorded in 16 of Pennsylvania’s 67 counties. Pennsylvania lists Common Buckthorn under “Class B.”

Common Frogbit – Hydrocharis morsus-ranae Not recorded hereInvasive

Common Frogbit (Hydrocharis morsus-ranae)
Photo by Christian Fischer / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Common Frogbit under “Class A.”

Common Wormwood – Artemisia vulgaris Not recorded hereInvasive

Common Wormwood (Artemisia vulgaris)
Photo by Doug Goldman / Public domain / USDA NRCS National Plants Data Team (NPDT) / via USDA PLANTS

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Common Wormwood under “Class B.”

Eurasian Watermilfoil – Myriophyllum spicatum IntroducedInvasive

Eurasian Watermilfoil (Myriophyllum spicatum)
CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 23 of Pennsylvania’s 67 counties. Pennsylvania lists Eurasian Watermilfoil under “Class B.”

European Swallow-Wort – Cynanchum rossicum IntroducedInvasive

European Swallow-Wort (Cynanchum rossicum)
Photo by Epibase / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 1 of Pennsylvania’s 67 counties. Pennsylvania lists European Swallow-Wort under “Class B.”

European Wand Loosestrife – Lythrum virgatum IntroducedProhibited

European Wand Loosestrife (Lythrum virgatum)
Photo by Stefan.lefnaer / CC BY-SA 4.0 / Wikimedia Commons

Recorded in 1 of Pennsylvania’s 67 counties. Pennsylvania lists European Wand Loosestrife under “Class B.”

Fig Buttercup – Ranunculus ficaria IntroducedInvasive

Fig Buttercup (Ranunculus ficaria)
Photo by Michal Osmenda from Brussels, Belgium / CC BY-SA 2.0 / Wikimedia Commons

Invasive in the US, and recorded in 10 of Pennsylvania’s 67 counties. Pennsylvania lists Fig Buttercup under “Class B.”

Fiveleaf Akebia – Akebia quinata IntroducedInvasive

Fiveleaf Akebia (Akebia quinata)
Photo by Unknown photographer / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 6 of Pennsylvania’s 67 counties. Pennsylvania lists Fiveleaf Akebia under “Class A.”

Garlic Mustard – Alliaria petiolata IntroducedInvasive

Garlic Mustard (Alliaria petiolata)
Photo by O. Pichard / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 38 of Pennsylvania’s 67 counties. Pennsylvania lists Garlic Mustard under “Class B.”

Giant Hogweed – Heracleum mantegazzianum Not recorded hereInvasive

Giant Hogweed (Heracleum mantegazzianum)
Photo by Lucas Kendall / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Giant Hogweed under “Class A.”

Giant Knotweed – Polygonum sachalinense IntroducedInvasive

Giant Knotweed (Polygonum sachalinense)
Photo by Velocicaptor at en.wikipedia / Public domain / Wikimedia Commons

Invasive in the US, and recorded in 23 of Pennsylvania’s 67 counties. Pennsylvania lists Giant Knotweed under “Class B.”

Glossy Buckthorn – Frangula alnus IntroducedInvasive

Glossy Buckthorn (Frangula alnus)
Photo by Sten Porse / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 16 of Pennsylvania’s 67 counties. Pennsylvania lists Glossy Buckthorn under “Class B.”

Japanese Angelica Tree – Aralia elata Not recorded hereInvasive

Japanese Angelica Tree (Aralia elata)
Photo by Tracey Slotta / Public domain / ARS Systematic Botany and Mycology Laboratory / via USDA PLANTS

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Japanese Angelica Tree under “Class B.”

Japanese Barberry – Berberis thunbergii IntroducedInvasive

Japanese Barberry (Berberis thunbergii)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Invasive in the US, and recorded in 51 of Pennsylvania’s 67 counties. Pennsylvania lists Japanese Barberry under “Class B.”

Japanese Hop – Humulus japonicus IntroducedInvasive

Japanese Hop (Humulus japonicus)
Photo by Mark A. Garland / Public domain / via USDA PLANTS

Invasive in the US, and recorded in 19 of Pennsylvania’s 67 counties. Pennsylvania lists Japanese Hop under “Class B.”

Japanese Knotweed – Fallopia japonica (potentially invasive weed) IntroducedInvasive

Japanese Knotweed (Fallopia japonica (potentially invasive weed))
Photo by Elaine Haug / CC0 / Smithsonian Open Access / via USDA PLANTS

Invasive in the US, and recorded in 43 of Pennsylvania’s 67 counties. Pennsylvania lists Japanese Knotweed under “Class B.”

Japanese Privet – Ligustrum japonicum Not recorded hereInvasive

Japanese Privet (Ligustrum japonicum)
Photo by José Luis Gálvez / CC BY-SA 2.5 / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Japanese Privet under “Class A.”

Johnsongrass – Sorghum halepense IntroducedInvasive

Johnsongrass (Sorghum halepense)
Photo by Forest & Kim Starr / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 13 of Pennsylvania’s 67 counties. Pennsylvania lists Johnsongrass under “Class B.”

Large-Flower Primrose-Willow – Ludwigia grandiflora IntroducedInvasive

Large-Flower Primrose-Willow (Ludwigia grandiflora)
Photo by Mark A. Garland / Public domain / via USDA PLANTS

Invasive in the US, and recorded in 3 of Pennsylvania’s 67 counties. Pennsylvania lists Large-Flower Primrose-Willow under “Class A.”

Louise's Swallow-Wort – Cynanchum louiseae IntroducedInvasive

Louise's Swallow-Wort (Cynanchum louiseae)
Photo by Part of a work by Britton, N.L., and A. Brown / Public domain / Wikimedia Commons

Invasive in the US, and recorded in 10 of Pennsylvania’s 67 counties. Pennsylvania lists Louise's Swallow-Wort under “Class B.”

Morrow's Honeysuckle – Lonicera morrowii IntroducedInvasive

Morrow's Honeysuckle (Lonicera morrowii)
Photo by Easai at English Wikipedia / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 42 of Pennsylvania’s 67 counties. Pennsylvania lists Morrow's Honeysuckle under “Class B.”

Multiflora Rose – Rosa multiflora IntroducedInvasive

Multiflora Rose (Rosa multiflora)
Photo by Famartin / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in 35 of Pennsylvania’s 67 counties. Pennsylvania lists Multiflora Rose under “Class B.”

Nepalese Browntop – Microstegium vimineum IntroducedInvasive

Nepalese Browntop (Microstegium vimineum)
Photo by James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org / CC BY 3.0 us / Wikimedia Commons

Invasive in the US, and recorded in 20 of Pennsylvania’s 67 counties. Pennsylvania lists Nepalese Browntop under “Class B.”

Nodding Plumeless Thistle – Carduus nutans IntroducedInvasive

Nodding Plumeless Thistle (Carduus nutans)
Photo by Andreiflorea993 / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in 18 of Pennsylvania’s 67 counties. Pennsylvania lists Nodding Plumeless Thistle under “Class B.”

Oriental Bittersweet – Celastrus orbiculatus IntroducedInvasive

Oriental Bittersweet (Celastrus orbiculatus)
Photo by Unknown photographer / Public domain / Wikimedia Commons

Invasive in the US, and recorded in 22 of Pennsylvania’s 67 counties. Pennsylvania lists Oriental Bittersweet under “Class B.”

Parrot Feather Watermilfoil – Myriophyllum aquaticum IntroducedInvasive

Parrot Feather Watermilfoil (Myriophyllum aquaticum)
Photo by Robert H. Mohlenbrock. USDA NRCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Invasive in the US, and recorded in 6 of Pennsylvania’s 67 counties. Pennsylvania lists Parrot Feather Watermilfoil under “Class A.”

Parsnip – Pastinaca sativa IntroducedInvasive

Parsnip (Pastinaca sativa)
Photo by Patrick J. Alexander / Public domain / via USDA PLANTS

Invasive in the US, and recorded in 64 of Pennsylvania’s 67 counties. Pennsylvania lists Parsnip under “Class B.”

Plume Grass – Saccharum ravennae (Erianthus ravennae) Not recorded hereProhibited

Plume Grass (Saccharum ravennae (Erianthus ravennae))
Photo by Daderot / Public domain / Wikimedia Commons

Recorded in no Pennsylvania county. Pennsylvania lists Plume Grass under “Class A.”

Poison Hemlock – Conium maculatum IntroducedInvasive

Poison Hemlock (Conium maculatum)
Photo by William & Wilma Follette. USDA NRCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Invasive in the US, and recorded in 35 of Pennsylvania’s 67 counties. Pennsylvania lists Poison Hemlock under “Class B.”

Professor-Weed – Galega officinalis IntroducedInvasive

Professor-Weed (Galega officinalis)
CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 3 of Pennsylvania’s 67 counties. Pennsylvania lists Professor-Weed under “Class A.”

Purple Loosestrife – Lythrum salicaria IntroducedInvasive

Purple Loosestrife (Lythrum salicaria)
Photo by Ivar Leidus / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 36 of Pennsylvania’s 67 counties. Pennsylvania lists Purple Loosestrife under “Class B.”

Roughfruit Amaranth – Amaranthus tuberculatus NativeProhibited

Roughfruit Amaranth (Amaranthus tuberculatus)
Photo by Unknown authorUnknown author / Public domain / Wikimedia Commons

Recorded in 8 of Pennsylvania’s 67 counties. Pennsylvania lists Roughfruit Amaranth under “Class A.”

Showy Fly Honeysuckle – Lonicera x bella IntroducedInvasive

Showy Fly Honeysuckle (Lonicera x bella)
Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org / CC BY 3.0 us / Wikimedia Commons

Invasive in the US, and recorded in 10 of Pennsylvania’s 67 counties. Pennsylvania lists Showy Fly Honeysuckle under “Class B.”

Sorghum – Sorghum bicolor IntroducedInvasive

Sorghum (Sorghum bicolor)
Photo by Pethan / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 22 of Pennsylvania’s 67 counties. Pennsylvania lists Sorghum under “Class B.”

Standish's Honeysuckle – Lonicera standishii IntroducedProhibited

Recorded in 5 of Pennsylvania’s 67 counties. Pennsylvania lists Standish's Honeysuckle under “Class B.”

Sunshine Chinese Privet – Ligustrum sinense 'Sunshine' Not recorded hereInvasive

Sunshine Chinese Privet (Ligustrum sinense 'Sunshine')
CC BY-SA 2.5 / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Sunshine Chinese Privet under “Class B.”

Tatarian Honeysuckle – Lonicera tatarica IntroducedInvasive

Tatarian Honeysuckle (Lonicera tatarica)
Photo by dave_7 from Lethbridge, Canada / CC BY 2.0 / Wikimedia Commons

Invasive in the US, and recorded in 24 of Pennsylvania’s 67 counties. Pennsylvania lists Tatarian Honeysuckle under “Class B.”

Tree of Heaven – Ailanthus altissima IntroducedInvasive

Tree of Heaven (Ailanthus altissima)
Photo by USDA Forest Service / Public domain / USDA Forest Service / via USDA PLANTS

Invasive in the US, and recorded in 36 of Pennsylvania’s 67 counties. Pennsylvania lists Tree of Heaven under “Class B.”

Water Chestnut – Trapa natans IntroducedInvasive

Water Chestnut (Trapa natans)
Photo by Krzysztof Ziarnek, Kenraiz / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in 3 of Pennsylvania’s 67 counties. Pennsylvania lists Water Chestnut under “Class A.”

Water Soldiers – Stratiotes aloides Not recorded hereProhibited

Water Soldiers (Stratiotes aloides)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Recorded in no Pennsylvania county. Pennsylvania lists Water Soldiers under “Class C.”

Waterthyme – Hydrilla verticillata Not recorded hereInvasive

Waterthyme (Hydrilla verticillata)
Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Pennsylvania county. Pennsylvania lists Waterthyme under “Class B.”

Wild Chervil – Anthriscus sylvestris IntroducedInvasive

Wild Chervil (Anthriscus sylvestris)
Photo by T. Kebert / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in 8 of Pennsylvania’s 67 counties. Pennsylvania lists Wild Chervil under “Class A.”

Wild Privet – Ligustrum vulgare IntroducedInvasive

Wild Privet (Ligustrum vulgare)
Photo by Rasbak / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in 26 of Pennsylvania’s 67 counties. Pennsylvania lists Wild Privet under “Class B.”

Yellow Floatingheart – Nymphoides peltata IntroducedInvasive

Yellow Floatingheart (Nymphoides peltata)
Photo by G.A. Cooper / CC0 / Smithsonian Open Access / via USDA PLANTS

Invasive in the US, and recorded in 2 of Pennsylvania’s 67 counties. Pennsylvania lists Yellow Floatingheart under “Class A.”

2 of these plants are native to part of the United States, marked US native above. Nativity is regional. Black locust is native to the Appalachians and regulated in New England; Palmer amaranth is native to the Southwest and listed as an agricultural weed in the Corn Belt. A listing tells you what Pennsylvania regulates, not where a plant belongs. The county checker answers the second question.

Want to check a plant by photo or county?

Use our “Is it native” tool for free.

Compiled from the rule itself, retrieved July 20, 2026. Law changes; if you spot a listing we have wrong or stale, tell us at support@getezina.com.

The same list as a table
Plant Scientific name Status Plant instead
Amur Honeysuckle Lonicera maackii ProhibitedInvasivePennsylvania says “Class B” Common Witch Hazel, Smooth Sumac, Shining Willow
Animated Oat Avena sterilis ProhibitedInvasivePennsylvania says “Class A” —
Asiatic Tearthumb Polygonum perfoliatum ProhibitedInvasivePennsylvania says “Class B” —
Basketgrass Oplismenus hirtellus ProhibitedPennsylvania says “Class A” —
Blood Grass Imperata cylindrica ProhibitedInvasivePennsylvania says “Class A” Velvet Bentgrass, Flatstem Spikerush, Purple Love Grass
Bohemian Knotweed Polygonum x bohemicum ProhibitedPennsylvania says “Class B” —
Border Privet Ligustrum obtusifolium ProhibitedInvasivePennsylvania says “Class B” White Meadowsweet, Sandcherry, American Black Currant
Brazilian Waterweed Egeria densa ProhibitedInvasivePennsylvania says “Class A” —
Bull Thistle Cirsium vulgare ProhibitedInvasivePennsylvania says “Class B” —
Burning Bush Euonymus alatus ProhibitedInvasivePennsylvania says “Class B” Russet Buffaloberry, Mapleleaf Viburnum, Coastal Serviceberry
Callery Pear Pyrus calleryana ProhibitedInvasivePennsylvania says “Class B” Paper Birch, Sassafras, Pin Cherry
Canada Thistle Cirsium arvense ProhibitedInvasivePennsylvania says “Class B” —
Carelessweed US native Amaranthus palmeri ProhibitedPennsylvania says “Class A” —
Common Buckthorn Rhamnus cathartica ProhibitedInvasivePennsylvania says “Class B” Common Witch Hazel, Smooth Sumac, Shining Willow
Common Frogbit Hydrocharis morsus-ranae ProhibitedInvasivePennsylvania says “Class A” —
Common Wormwood Artemisia vulgaris ProhibitedInvasivePennsylvania says “Class B” Common Sneeze Weed, Canadian Milkvetch, Purple Coneflower
Eurasian Watermilfoil Myriophyllum spicatum ProhibitedInvasivePennsylvania says “Class B” —
European Swallow-Wort Cynanchum rossicum ProhibitedInvasivePennsylvania says “Class B” —
European Wand Loosestrife Lythrum virgatum ProhibitedPennsylvania says “Class B” Great St. Johnswort, Canada Goldenrod, Common Cowparsnip
Fig Buttercup Ranunculus ficaria ProhibitedInvasivePennsylvania says “Class B” Longbeak Buttercup, Beach Pea, Blue Eyed Grass
Fiveleaf Akebia Akebia quinata ProhibitedInvasivePennsylvania says “Class A” —
Garlic Mustard Alliaria petiolata ProhibitedInvasivePennsylvania says “Class B” —
Giant Hogweed Heracleum mantegazzianum ProhibitedInvasivePennsylvania says “Class A” —
Giant Knotweed Polygonum sachalinense ProhibitedInvasivePennsylvania says “Class B” —
Glossy Buckthorn Frangula alnus ProhibitedInvasivePennsylvania says “Class B” Shining Willow, Speckled Alder, Eastern Baccharis
Japanese Angelica Tree Aralia elata ProhibitedInvasivePennsylvania says “Class B” Hercules's Club, Fireberry Hawthorn, Shining Willow
Japanese Barberry Berberis thunbergii ProhibitedInvasivePennsylvania says “Class B” White Meadowsweet, Blue Huckleberry, Mountain Laurel
Japanese Hop Humulus japonicus ProhibitedInvasivePennsylvania says “Class B” —
Japanese Knotweed Fallopia japonica (potentially invasive weed) ProhibitedInvasivePennsylvania says “Class B” —
Japanese Privet Ligustrum japonicum ProhibitedInvasivePennsylvania says “Class A” —
Johnsongrass Sorghum halepense ProhibitedInvasivePennsylvania says “Class B” —
Large-Flower Primrose-Willow Ludwigia grandiflora ProhibitedInvasivePennsylvania says “Class A” —
Louise's Swallow-Wort Cynanchum louiseae ProhibitedInvasivePennsylvania says “Class B” —
Morrow's Honeysuckle Lonicera morrowii ProhibitedInvasivePennsylvania says “Class B” White Meadowsweet, Sandcherry, American Black Currant
Multiflora Rose Rosa multiflora ProhibitedInvasivePennsylvania says “Class B” American Black Currant, Coastal Serviceberry, White Meadowsweet
Nepalese Browntop Microstegium vimineum ProhibitedInvasivePennsylvania says “Class B” —
Nodding Plumeless Thistle Carduus nutans ProhibitedInvasivePennsylvania says “Class B” —
Oriental Bittersweet Celastrus orbiculatus ProhibitedInvasivePennsylvania says “Class B” American Bittersweet, Trumpet Honeysuckle, Yellow Passionflower
Parrot Feather Watermilfoil Myriophyllum aquaticum ProhibitedInvasivePennsylvania says “Class A” —
Parsnip Pastinaca sativa ProhibitedInvasivePennsylvania says “Class B” —
Plume Grass Saccharum ravennae (Erianthus ravennae) ProhibitedPennsylvania says “Class A” —
Poison Hemlock Conium maculatum ProhibitedInvasivePennsylvania says “Class B” —
Professor-Weed Galega officinalis ProhibitedInvasivePennsylvania says “Class A” —
Purple Loosestrife Lythrum salicaria ProhibitedInvasivePennsylvania says “Class B” Great St. Johnswort, Canada Goldenrod, Common Cowparsnip
Roughfruit Amaranth US native Amaranthus tuberculatus ProhibitedPennsylvania says “Class A” —
Showy Fly Honeysuckle Lonicera x bella ProhibitedInvasivePennsylvania says “Class B” White Meadowsweet, Sandcherry, American Black Currant
Sorghum Sorghum bicolor ProhibitedInvasivePennsylvania says “Class B” —
Standish's Honeysuckle Lonicera standishii ProhibitedPennsylvania says “Class B” —
Sunshine Chinese Privet Ligustrum sinense 'Sunshine' ProhibitedInvasivePennsylvania says “Class B” —
Tatarian Honeysuckle Lonicera tatarica ProhibitedInvasivePennsylvania says “Class B” American Fly Honeysuckle, Swamp Fly Honeysuckle, American Black Currant
Tree of Heaven Ailanthus altissima ProhibitedInvasivePennsylvania says “Class B” Western Catalpa, Kentucky Coffeetree, Post Oak
Water Chestnut Trapa natans ProhibitedInvasivePennsylvania says “Class A” —
Water Soldiers Stratiotes aloides ProhibitedPennsylvania says “Class C” —
Waterthyme Hydrilla verticillata ProhibitedInvasivePennsylvania says “Class B” —
Wild Chervil Anthriscus sylvestris ProhibitedInvasivePennsylvania says “Class A” —
Wild Privet Ligustrum vulgare ProhibitedInvasivePennsylvania says “Class B” White Meadowsweet, Sandcherry, American Black Currant
Yellow Floatingheart Nymphoides peltata ProhibitedInvasivePennsylvania says “Class A” —

What the tags mean

Two separate findings. Invasive is ecological. The other three are legal statuses Pennsylvania sets in statute, and which one applies turns on what the rule obliges, and of whom.

Invasive
An ecological finding, and a different question from the law. GRIIS — the Global Register of Introduced and Invasive Species — lists the plant as invasive in the lower 48 states. Most invasive plants carry no state listing at all and are sold freely, so a plant without this tag is not thereby safe, and a plant without a legal chip is not thereby harmless.
Prohibited
May not be sold, moved, propagated or possessed at all.
Restricted
May still be sold or held, but under conditions — retail signage, an identification tag, or a carve-out for sterile cultivars.
Listed
Designated, but the duty to control it falls on landowners rather than on the nursery trade.

Where this comes from

Pennsylvania listings
3 Pa.C.S. 1501-1562 (Act 46 of 2017). Read the rule.
Invasive status
GRIIS, the Global Register of Introduced and Invasive Species, via GBIF, covering the lower 48 states. A scientific register with no legal force; it is cited separately from the statute above because the two disagree far more often than they agree. Garden crops it flags only for spreading from cultivation are left out after review.
Status wording
The Prohibited / Restricted / Listed chips are Ezina’s normalisation across 44 states and are not the legal term. Where Pennsylvania’s own word for a plant differs from the chip, it is quoted verbatim beneath it.
Nativity
USDA PLANTS county distribution layer, surfaced through the county checker.

Regulated next door, but not in Pennsylvania

Plants that two or more states bordering Pennsylvania regulate, and Pennsylvania does not. A listing is a legal act rather than an ecological one, so a plant can be a documented problem here and still be sold here.

Questions

Is there an official Pennsylvania invasive species list?

Yes. 3 Pa.C.S. 1501-1562 (Act 46 of 2017) is Pennsylvania's list, naming 57 plants under a trade restriction, which governs what may be sold, propagated, or moved within the state — in plain terms, which plants are illegal to sell here. GRIIS, the Global Register of Introduced and Invasive Species, flags 49 of these 57 as invasive in the lower 48 states. That is an ecological finding, not a ruling by Pennsylvania. This page shows both side by side.

What plants are illegal to sell in Pennsylvania?

57 plants are regulated under 3 Pa.C.S. 1501-1562 (Act 46 of 2017). Plants marked Prohibited may not be sold, propagated, or moved within Pennsylvania. Plants marked Restricted carry narrower limits set by the rule.

Is my plant invasive in Pennsylvania?

Search the table on this page for Pennsylvania's legal determination, then look for the Invasive chip beside it, which is a separate ecological finding from GRIIS rather than a ruling by Pennsylvania. A plant can carry one, both, or neither. For an address-level answer, enter the plant's name in Ezina's checker to get its Pennsylvania status alongside whether USDA records it as native to your specific county. Every answer links the record it came from.

Is it illegal to plant these in Pennsylvania?

For the plants marked Prohibited, 3 Pa.C.S. 1501-1562 (Act 46 of 2017) bars selling, propagating, or moving them within Pennsylvania. Whether planting one you already own is itself an offence depends on that rule's exact wording, which is why every plant on this page links the citation rather than us paraphrasing it. Plants marked Restricted carry narrower limits the rule sets out.

Does a plant missing from this list mean it is safe to plant in Pennsylvania?

No. This page reproduces what Pennsylvania regulates, and a state list is a legal instrument rather than an ecological verdict. Plenty of plants spread aggressively without ever being listed, and states add species years after the problem is documented.

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010.1Identify

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010.2Care

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Snap a photo or type the name. Ezina matches it to a library of about 40,000 species and starts a care plan tailored to your zone, the local weather, and the time of year.

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