Mysterious unknown plants

The first 2 pics are of the same plant/tree it has grown a huge amount in one season and is obviously something that has set seed and not actually been planted.

3rd pic, it looks familiar but I need some help. It's been flowering for a long time now and is still going, upright habit, not much more I can tell you.

4th pic, flowering now, herbaceous perennial I think, its growing in pretty dense shade.

Thank you so much, it's driving me mad not knowing what they are.

Hi AliP

3rd pic, I believe, is a form of spiraea.  I have it in my garden, and the same - is flowering still.

The 4th is chelone - deep green foliage and pink flowers in late summer and likes shade.  There's also a white form available but the pink version is stronger.  Mine is very happy and spreading slowly.  I love it.  It looks great next to a big fat hosta Sum and Substance.

The third looks like spiraea douglasii .

The plant shown in pics 1 and 2 looks very much like laurel.

If so, it forms a nice shrub or hedge, if you have the space. But it can become very large. Laurel seedlings can turn up, especially if there's a bush/tree nearby.

Pics 1 and 2 are Juglans regia or Common Walnut. I agree with Obelixx about pics 3 and 4.

Thank you all so much! Yes definitely Spiraea douglasii & Chelone.  I'll crush the leaves on the walnut just to check, looks like it could be though. Thank you again this has saved me alot of time looking in books etc.

Not familiar with pics 1 & 2. 

3 a Spirea. I cut mine down a bit after the flowers finish & then redo it in the spring when you can see the buds starting to break.

4. Chelone, or Turtlehead. You can do the Chelsea chop on a clump to keep it shorter if you want. I find mine is happy in both sun & part shade & on dry or slightly moister soil. Yes the pink is more vigorous, but the white one is nice too. J.