Rushes or Grasses?

Lots of lovely rushes type plants stabilising the banks of Rusland Pool. 

We could see they were not bullrushes because they had the wrong flowers. Google Lens told us they were Common Reeds. 

That's interesting I said to my walking partner, are they rushes or grasses? Do you know that little rhyme:- 
Sedges have edges,
Rushes are round, 
Grasses have nodes all the way to the ground

Well these reeds definitely have nodes all the way to the ground so they are grasses not rushes.