Yes, this appears to be Japanese knotweed (Fallopia japnoica), though it could also be giant knotweed (Fallopia sachalinesis). Either way it is considered invasive in Michigan.

Below is some detailed information I have on Japanese knotweed, that would also apply to giant knotweed. Another consideration would be contacting the GiLLS CISMA (i.e. Cooperative Invasive Species Management Area for Genesee, Lapeer, Livingston, and Shiawasee counties. They may have programs to assist you in control, detailed recommendations for your site, or other resources to help you combat this invasive (e.g. rental equipment, etc.). Their website is https://www.geneseecd.org/invasives The coordinator is Patric Scanlon, <personal data hidden>,<personal data hidden>. 

Japanese knotweed (Fallopia japonica) is an aggressive perennial that reproduces both by rhizomes (underground stems) and by seed. It is often found in shaded to partially shaded habitats on moist, nutrient-rich soils, though it can thrive in gardens and on roadsides as well.

Physical control.

Repeated chopping or digging may eventually deplete underground reserves thus reducing the competitive edge of Japanese knotweed, however it is expected to take several growing seasons to achieve eradication. Both root and stem fragments can root and result in new plants, therefore any plant material removed for control should be placed in the trash headed to the landfill and not in yard waste or compost. Mulching is not an effective means of suppressing Japanese knotweed. Mowing is not recommended as it can spread the infestation.

Biological control.

At MSU Dr. Marianna Szucs laboratory group is working on a testing a biological control agent for Japanese knotweed, however this is still in the preliminary stages of testing for the state. More information Dr. Szucs program can be found at http://mariannaszucs.weebly.com/ in the Resources section.

Chemical control.

Repeated herbicide applications of glyphosate or various brush killers, such as triclopyr (Garlon, Pathfinder, Brush-B-Gon), picloram (Tordon, Pathway) or triclopyr + 2,4-D (Crossbow) should help keep this plant under control, but eradication is difficult. Chemical applications can be made to cut stems for more effective treatment of small populations, see herbicide labels for details. Glyphosate (e.g. Roundup Weed and Grass Killer concentrate) is probably the best choice for homeowners because of its safety, ease of application and lack of residual activity in the soil. Glyphosate is most effective for perennial control in the fall but can be applied anytime the plants are actively growing (temperatures consistently above 50F). Repeat applications may be necessary.

When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).

There are more potent herbicides available that may provide eradication, but they are very persistent and can impact trees and shurbs with roots in the area. If you would like more information on these herbicides please contact me via email at <personal data hidden>.