Numerous plants have been introduced to the US state of Pennsylvania in the last four hundred years and many of them have become invasive species that compete with the native plants and suppress their growth.
Invasive species are often grouped by threat levels that vary from county to county from very high impact to remarkable increased growth. The species below are by no means comprehensive and are listed in type order rather than level of threat[1] [2] [3]
The Pennsylvania Department of Conservation and Natural Resources ranks invasive species into 3 categories based on urgency of threat. [4]
| class=unsortable | Picture | Scientific Name | Common Name |
|---|---|---|---|
| Acer platanoides | Norway maple | ||
| Ailanthus altissima | tree of heaven | ||
| Alliaria petiolata | garlic mustard | ||
| Aralia elata | Japanese Angelica tree | ||
| Berberis thunbergii | Japanese barberry | ||
| Euonymus alatus | Winged Spindle | ||
| Lonicera japonica | Japanese honeysuckle | ||
| Phragmites | |||
| Reynoutria japonica | Japanese knotweed | ||
| Rhamnus cathartica | Buckthorn | ||
| Rhodotypos scandens | Jetbead | ||
| Rosa multiflora | Multiflora Rose | ||
| Rubus phoenicolasius | Japanese wineberry | ||
| Saccharum ravennae | Ravenngrass | ||
| Frangula alnus | Alder Buckthorn | ||
| Galega officinalis | goat's-rue | ||
| Heracleum mantegazzianum | Giant Hogweed | ||
| Phellodendron | Cork-Tree | ||
| Pueraria | Kudzu | ||
| Vincetoxicum nigrum | Black Swallowwort | ||
| Vincetoxicum rossicum | Pale Swallowwort | ||
| Morus alba | White Mulberry |