English Ivy (Hedera helix) on a Oregon White Oak (Quercus garrayana). If left, the ivy can smother a tree.
English Ivy vines on the truck of a oak tree have grown to more than 3 inches thick.
Careful removal with a chainsaw.
Invasive Yellow flag-iris (Iris pseudacorus) in a marsh.
Purple Loosestrife (Lythrum salicaria) on the Lewis and Clark National Wildlife Refuge with The Nature Conservancy's Blind Slough Swamp Preserve in the background.
Known as Sweet Violet, English Violet, Common Violet, or Garden Violet (Viola odorata) is not native to Oregon but was introduced from Europe and Asia.
Herb Robert (Geranium robertianum) is becoming one of the most common invasive species in western Oregon.
Invasive Eastern Gray Squirrels (Sciurus carolinensis) in Western Oregon
Virginia Opossum (Didelphis virginiana) is considered an Invasive Species in Oregon.
