Does anyone know what this is? It doesn't appear to have flowers per se, so a
grass of some sort?
I would say one of the millets - escaped from bird seed,
I think I agree with PeterE17. I have had 4 of these pop up this year - am letting them grow to see what happens.
Originally, I thought I met get some corn on the cob.....
I'm doing the same, quite pretty in their own way. Would've been nice is it had been corn of the cob!