|Rushes, cattail, and boneset at the water's edge|
I must say that identification of grasses, sedges, and rushes is not something I excel at. In fact, I'm usually pretty bad at it but I can get the right grouping for the plant without any effort -- you have to love mnemonics! Here's what I know plus a couple of variations I've heard on it:
Sedges have edges, rushes are round, and grasses have joints.Maybe this will help you get your plant into the right grouping as well!
Sedges have edges, rushes are round, and grasses are hollow right up from the ground.
Sedges have edges, rushes are round and grasses have knees that bend to the ground.