Which species is that ?

I'm going to start a thread where to ask questions about any plant anyone of us encounters.
The "game" is straightforward:
you can add a picture in attachment and then you ask:
"which species is the one in the picture ???"
Any kind of plant: be it a tree, a herb, a weed or what-have-you.

I start the "game".
I add in attachment some pictures of a weed that I encountered in the London Royal Parks.
I've recently been to London and, as a "Martian" landed in a "new planet" :D (the Big Grin smilie is because it is green like the Martians...) , I took a lot of pictures of the various plants & trees.
Expecially of those that I heven't seen before in my "planet" (Milan -Northern Italy).
LIKE THE ONE IN ATTACHMENT. WHICH SPECIES IS IT ???
In my "planet" - Northern Italy - I've never seen it before.
So I decided to pick it up (as a "sample" of "moon rock" :hehe and to take a picture of it.

 

...and here a high-zoomed picture taken to the "sample" of the same weed picked up (as it were a "moon rock sample" :hehe.

 

Thank you for your reply, Marley.
It might be "Achillea".
I have read something about "Achillea" and I have seen some pictures of that.
Yes, it might be "Achillia".
According to what I have read, "Achillea" is a plant widespread in the whole northern emisphere (North America, Europe, North Asia).
Furthermore, according to that, it looks like it is a plant that does not like too hot climates.
Accordingly, we can find it in Sweden, in mountain regions of Switzerland and - in Italy - it grows even in the mountain areas topping 10,000 feet of altitude.
Probably the "cool-oriented" habitat of this plant is the reason why I've never seen it in my local area (Northern Italy).
Indeed, although the Northern Italy climate is not exactly a "warm one" in winter (absolutely, not at all), it defenetely "switch" to a sub-tropical climate by summer-time, during which time the average high temperatures are often well above 30 C, and the average low temperatures never drop below 20 C. Probably, these wheather conditions are too hot for Achillia.
On the contrary, in London area (and, I guess, in the whole Britain) there are the ideal conditions for this plant: summer average low temperatures around 15 C (or cooler) and summer average high temperatures not above 25 C (often closer to 20 C and seldom - probably not more that just a few days in the year - close or above 30 C).

 

Another name for it is Yarrow. There are wild and cultivated varieties - the wild variety has creamy white flowers and is fairly low growing, the cultivated varieties are many.