Norway Maple (Acer platanoides) Japanese Barberry (Berberis ...

Cespitose knotweed (Polygonum cespitosum)
Status: Invasive.
Native to: Europe.
Effects: This plant is mildly toxic so it has few natural
predators. It is able to thrive in moist habitats,
dominating the substrate and thus necessary nutrients,
water, and sunlight to the detriment of native species.
Distinctive features: This is a slender herbaceous plant
that can reach sixteen inches in height. Leaves
alternate along the stem and can reach three inches in
length and one inch in width. The flowers are reddish
pink and white and occur between May and September.
This species can be recognized by presence of a
characteristic purple splotch in the center of the leaf
which is present in many but not all specimens.
http://www.missouriplants.com/Redalt/Polygonum_cespitosum_
page.html
Bulbous buttercup (Ranunculus bulbosus)
Status: Exotic.
Native to: Europe.
Effects: A common weed of lawns, pastures, and hay
fields, it can cause blisters in the mouth and intestinal
tracts of cattle if accidentally eaten.
http://www.floralimages.co.uk/images/ranunculus_bulbosus_93f.jpg
Distinctive features: The base of the plant is
thickened into a structure known as a corm, which
resembles a bulb, a feature not shared by other similar
species. Sprouting from the corm are usually several
grooved, hairy stems, each of which can grow up to 18”
tall. Its leaves are divided into 3 parts and are sharply
toothed. This plant is most easily recognized by its
distinctive, yellow flowers. The 5 petals are so shiny
that they reflect light. The hairy green sepals that
surround the flower bend back toward the stem.