National Invasive Species Awareness Week: Michigan species and what you should know, day four

Bindu Bhakta<bhaktabi@msu.edu>, Michigan State University Extension and Mary Bohling, Michigan State University Extension, Sea Grant Program - February 24, 2016

Day four: Featured Michigan terrestrial invasive species is Japanese Stilt Grass.

Japanese stilt grass has a “petite bamboo” appearance and assymetrical lance-shaped leaves Photo credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

National Invasive Species Week 2016 is Feb. 21-27. Invasive species are plants, animals, and other organisms that are not traditionally found in a given location (in this case the Great Lakes) and are having a negative impact of some kind, whether ecological, economic, social, and a public health threat.

To help bring awareness to this week, each day Michigan State University Extension (MSU Extension) and Michigan Sea Grant are featuring two different invasive species (one aquatic and one terrestrial species) that have invaded or has the potential to invade Michigan’s environment. Today’s featured terrestrial invasive species is Japanese stilt grass.

Species Name:

Japanese Stilt Grass (Microstegium vimineum). Japanese Stilt grass is a terrestrial invasive grass that is currently on the Michigan watch list. According to the Michigan Department of Environmental Quality, invasive species on the watch list are priority species that have been identified as being an immediate and significant threat to Michigan's natural resources. Watch list species either have never been confirmed in the wild in Michigan or have a very limited known distribution, or are localized. In the case of Japanese stilt grass, it has not yet been detected in Michigan.

Description:

Japanese stilt grass resembles small, delicate bamboo that can grow two to three feet tall. It has asymmetrical leaves that are pale green and lance-shaped. It is extremely shade-tolerant and can tolerate full sun exposure as well as deep shade. It prefers to grow in moist, rich soils.

Native look-alikes and how you can tell them apart from Japanese stilt grass:

This vine is similar in appearance to native whitegrass (Leersia virginica), but whitegrass has hairy stem nodes that Japanese stilt grass does not possess. In addition, native whitegrass has scaly roots whereas stilt grass has fibrous roots.

Origin:

Japanese stilt grass is native to Southeast Asia (China, Japan, Korea, Malaysia, and India).

Details of its introduction into the U.S.:

It was introduced into the United States via Tennessee around 1919. Japanese stilt grass likely escaped as a result of is use as a packing material for porcelain.

How long it has been here:

According to Midwest Invasive Species Information Network (MISIN), Japanese stilt grass has been in the United States since 1919.

Extent of range:

Japanese stilt grass has been detected in the southeast portion of the United States, from New York west to Texas. It has not yet been detected in Michigan. The MISIN web site shows the latest locations where this plant has been observed across the United States.

Why it is a problem:

Japanese stilt grass relies on disturbance to help it spread where it displaces native vegetation in the understory by forming dense patches.

How it is spread:

Japanese stilt grass reproduces prolifically via seed. One plant can produce up to 1,000 seeds per plant. Seeds can remain viable for three to five years. Seeds may be dispersed by water.

Cool/unusual fact:

Seeds can be easily attach to animals such as deer, the clothing of hikers, and may also be transported by all-terrain vehicles.

Management actions/options:

Japanese stilt grass can be challenging to control due to its ability to produce a large amount of seed. It is important to take the time in the fall to carefully monitor shady paths, roadsides, and along ditches and streams so it can be detected before the population proliferates. Hand-pulling must be done carefully since soil disturbance may increase germination where there are a lot of seeds present. Mowing should be done in the fall when it is flowering but before seed set occurs. Carefully review herbicide products that control Japanese stilt grass, as some herbicides do not kill this species.

What you can do to help prevent the spread:

Early detection and timely reporting of occurrences of Michigan watch list species such as Japanese stilt grass are crucial to minimizing the spread and limiting negative ecological and economic impacts. It should be reported immediately to Sue Tangora, Michigan DNR Wildlife Division (tangoras@michigan.gov). Take several photos of the plant and make note of the location, date and time of the observation as this will be very helpful in the verification of the report. You may be asked to provide your name and contact information if follow-up is needed. You can also use the Midwest Invasive Species Information Network (MISIN) online reporting tool. MISIN also offers a smartphone app that allows convenient reporting from a phone.

MSU Extension