Tree Shaped Tombstones - Union Cemetery

When on the back roads doing my Strange Fishing Challenge I run across other unexpected things.  Here is a small cemetery I had never been past.

Lo and behold, a Tree Shaped Tombstone.  Spaeth is a fairly common name in these parts.

Somethings slightly curious about this one.  It is clearly a "single stage" tombstone, not one of the big ones made up of two or even three segments.  Those monuments are held together with a metal rod placed in central holes of the segments.  So why is there a hole in this one?  I'm going to have to examine the tops of these things more closely.