Hard to determine from the dead stems but I do believe you are dealing with siricea lespedeza, (not sure about the spelling) but it is an invasive species here in MO that takes over any ground left bare, It was introduced here in the states by governmental agencies as a ground cover erosion control and became invasive like so many non native things they have introduced.
you might look it up on the MO Conservation website or any internet search platform. you will be able to tell better by looking at live pictures of it,, it is pretty hard to control but I do believe that the MO Conservation Dept will assist you in eradicating it I think if you have a big enough problem with it. hope that helps, and this may be a completely useless post if thats not even what it is.
