PropertyName.1 showing up when using reflection to log property names

I am logging the state of my application by first logging the name of every property in each of my classes, and then subsequently logging the values of those fields. The result of this is a time indexed table where the first row is a header row with column names, and all rows under it contain the value for each field at that time. One of my classes has a property called BasePosition, and in my header in addition to it I am seeing a BasePosition.1. I did a search for that variable name in my solution and nothing comes up. What is causing this?