A fairy ring!
This is very cool indeed--an annular growth of pitcher plants. If these were mushrooms, you might call this a fairy ring.
I wonder if this ring of pitchers was caused by the fire? Perhaps the fire, fueled by all the dead pitchers in the clump, was
hot enough to kill the rhizomes in the middle of the clump, while the rhizome tips on the edge of the clump survived?
Otherwise, you really would expect at least a few pitchers in the middle of the ring.
Or perhaps this is actually a UFO landing site.