For sedge sliver, do you also need a swamp for the regenerate ability or just the +1/+1. There seems to be some confusion on this with the double parenthesis.
These don't refer to each other in any way. The first requires a Swamp because it explicitly says so. The second doesn't (though it does require a source of black mana, and a Swamp would normally be the easiest way to provide that).