It sure looks like miscanthus that maybe got a hard killing frost before the seed head formed fully.
A stand like would surely be for biofuel and should have been harvested over the winter after the blades fell off.
Though there is still time to harvest.
If you get near it again look at the bottom of some of the stems for a rhizome.
Like this one. It will be brown and dead but if it's miscanthus 85% of them should have it.
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