Birdsfoot Trefoil (Lotus corniculatus)
This plant forms a thick mat, choking out all other groundcovers. It was introduced
as livestock fodder and erosion control and is a particular problem along the St.
Canada Thistle (Cirsium arvense)
Despite its name, this weed hails from Europe. It is one of the first species to
become established after a fire. Although 80 types of insects feed on it, its spread
Cornflower (Batchelor's Button) (Centaureacyanus)
This common plant has a long-lasting blue flower that likes pristine grassland habitats.
It is often included in commercial wildflower seed mixes.
Crown Vetch (Coronilla varia)
A prolific goundcover planted along our highways to control erosion. It will climb
over shrubs, shading them out. It should only be planted where it can be contained.
Dame's Rocket (Hesperis matronalis)
Sometimes mistakenly called wild phlox, the Europena immigrant escaped cultivation and
went wild in the 19th century. It excludes native species along roadsides and forest
Garlic Mustard (alliara petiolata)
This is the "purple loosestrife" of the forests. This weed dominates a
forest very easily, and is extremely difficult to get rid of once it is established.
It dominates a woodland and excludes all other forest floor plants.
Periwinkle (Vinca minor)
This is a pretty shade-tolerant evergreen groundcover that can persist for generations and
crowd out native vegetation. Please only use it where it cannot escape into local
Purple Loosestrife (Lythrum salicaria)
The effect of this plant of marshes has been well publicized, and many know of its
effects. Our wetlands may never be the same again, although there have been some
encouraging strides made in control of this plant. Given free reign, purple
loosestrife chokes out all other plant life in a marsh.