Growing (oddly) in my yard

Now, I've never claimed to have a green thumb. The things that grow best in my yard are the ones that planted themselves, or that someone else planted for me, and that simply need the occasional watering by me.
The red hot pokers are of the first variety. They were growing here when we moved in, though I didn't realize it until months later, in the spring. They usually look like this:

Although they are usually farther along by this time of year. We've had a prolonged cool spring that has slowed them a bit, but they almost always bloom for my birthday, which is nice of them.
However, this year, I'm seeing some....oddness. A couple of the flowers have forked like this:

And one has a 3-way going on like this:

Maybe I used too much of the Dr. Strangelove's Atomic Fertilizer?

These purplish feathery flowers have planted themselves and spread far and wide. Does anybody know what they are?