Invasive Plant Species in the Norwalk River Watershed

Two great new sources of information on invasive plants:

• Invasive of the Month Really helpful information and pictures for identification and control.
• Invasive Plants in Winter In the menu in Need to Identify pull-down menu: click on Invasive Plants in Winter; then Hot to Choose a View, click on Browse – Show ALL; then hit the “Start the ID!”

The following plants are invasive species (or are potentially invasive) within the Norwalk River watershed.  They crowd out the region's traditional plantlife, converting a healthy diversity of species into an unhealthy monoculture.  These plants are to be avoided, managed, or removed throughout the watershed. (This list was compiled June 1998).  

TREES
Norway Maple  Acer platanoides
Sycamore Maple  Acer pseudoplatanus
Tree-of-heaven  Ailanthus altissima
White Mulberry  Morus alba
Empress-tree  Paulownia tomentosa
Amur Cork Tree  Phellodendron japonicum
White or Poplar Cottonwood  Populus alba
Black Locust  Robinia pseudoacacia

SHRUBS
Japanese Barberry  Berberis thunbergii
Russian Olive  Elaeagnus angustifolia
Autumn Olive  Elaeagnus umbellata
Winged Euonymus  Euonymus alatus
Amur Honeysuckle  Lonicera maackii
Morrow's Honeysuckle  Lonicera morrowii
Tartarian Honeysuckle  Lonicera tatarica
Blunt-leaved Privet  Ligustrum obtusifolium
Common or European Privet  Ligustrum vulgare
Wineberry  Rubus phoenicolasias
Common or Smooth Buckthorn  Rhamnus cathartica
Glossy or Shining Buckhorn  Rhamnus frangula
Multiflora Rose  Rosa multiflora
Japanese Rose  Rosa rugosa


VINES
Porcelain Berry  Ampelopsis brevipedunculata
Asiatic Bittersweet  Celastrus orbiculatus
Japanese Honeysuckle  Lonicera japonica
Mile-a-Minute Vine  Polygonum perfoliatum
Kudzu  Pueraria lobata

HERBACEOUS PLANTS
Purple Loosestrife  Lythrum salicaria
Garden Loosestrife  Lysimachia vulgaris
Japanpese Knotweed  Polygonum cuspidatum
Yellow Flag Iris  Iris pseudacorus
Common Reed  Phragmites australis
Garlic Mustard  Alliaria petiolata
Japanese Stilt Grass  Microstegium vimineum
Leafy Spurge  Euphorbia esula
European Water-milfoil  Myriophyllum spicatum
Cottonweed  Froelichia gracilis
Goutweed  Aegopodium podagraria
Black Swallow-wort  Vincetoxicum nigrum
White Swallow-wort  Vincetoxicum hirundinaria