How to Identify Non-native Invasive Plants

How to Identify Non-native

Invasive Plants

Cynthia Sandeno, EcologistMonongahela National Forest

March 20, 2012

What We Will Cover Today:• Learn how to ID plants using:

o Growth cycles o Leaf typeso Leaf arrangementso Leaf margins

• Learn how to ID:o Autumn-oliveo Japanese knotweedo Japanese stiltgrasso Tree-of-heaveno Garlic mustard

Growth CyclesAnnual : plants that perform their entire life cycle from seed to flower to seed within one growing season.

Biennial : plants which require two years to complete their life cycle.

Perennial : any plant that persists for three or more growing seasons.

Japanese Stiltgrass Garlic Mustard Tree-of-heaven

Leaf Types

Node

Leaflet

Midrib

Leaf Arrangements

Leaf Margins

Entire/Smooth leaf Toothed leaf

Autumn-olive

Why was this invasive plant introduced into the U.S.?

Autumn-olive

Leaves: small and oval, dark green on the upper surface and silvery below. Small

coppery dots occur on stems and leaves.Flowers: light yellow and has a very strong odor.Fruits: a lot of red, small, and round fruits.

Can reach up to 20 ft. in height!

Japanese Knotweed

Why was this invasive plant introduced into the U.S.?

Japanese Knotweed

Stems: are smooth and hollow (like bamboo). Stem is zigzagged.Leaves: pointed leaves vary from broadly oval to almost

triangular, but they always have a squarish base.Flowers: sprays of small greenish-white flowers.

Affects water quality and fish habitat!

Japanese Stiltgrass

How did this plant get into the U.S.?

Japanese Stiltgrass

Leaves: pale green and lance-shaped with a distinct sliver stripe along the middle of the leaf.

•Has very shallow roots.•Can grow 2-3 ft. in height.

Tree-of-heaven

What country is this invasive native?

Tree-of-heaven

Leaves: compound and each leaflet is entire except for 1-2 rounded teeth at

the base.

Underside of each leaflet has a round gland near the “thumb”.

Flowers: small, yellow-green near tips of branches.

Garlic Mustard

Garlic Mustard

• Rosettes consisting of 3-4 kidney-shaped leaves • Leaves are coarsely toothed

•Between 2 and 4 feet in height•Triangular leaves with toothed edges•Clusters of small white flowers• 4 petals in a cross shape

First year plant Second year plant

Leaves smell like garlic when crushed!

Garlic Mustard-Look-alike Species

Sweet white violet Garlic mustard

Getting Rid of Garlic Mustard!