Hello,
Thank you for submitting your pictures with your great description.   This weed does look like it is in the family of grasses, Poaceae. 

I would like to get a little more information.  Can you tell me the location of where this is growing (lawn flower bed etc.)?  I am interested in getting a closer look at the seed head and root system.  If you could upload additional pictures it will help. 

I will watch for your reply.  Thank you!

Hi Barbara H,
Here are the additional photos you requested.
Thanking you in advance for your help.

This is appears to be a very large specimen of large crabgrass (Digitaria sanguinalis). Typically we think of this species of reaching a max height around 3 feet...but it could be possible depending on the environment for it to be larger. Large crabgrass is an annual species that is introduced to Michigan and found throughout much of the state. It reproduces only by seed, so it would be recommended to remove those seed heads as soon as possible to prevent future infestations. If you have further questions regarding control please feel free to email me directly at <personal data hidden>. If you do reach out, please include a description of the site and any desirable plants in the area. 

thank you, Erin and Barbara.,  I'll take your recommendation about the seed heads.  Good to know it's not perennial