Can anyone identify the brown stains seen here on the perimeter of these petals?
It's not on all of them, but a fair amount. Is this the "rust" that I've been reading about?

Any help would be great.

Thanks

This is not rust. I would guess those are older flowers about to die, or this could be from an overabundance of water.

Rust leaves a bright yellow (almost pollen-like) powder on the back of leaves.