My wife regularly makes up a posy for our kitchen and kitchen table.
Yesterday and today, the combination is a little bunch of Forget-me-not (Myosotis sylvatica) pulled by my grandson and a few little sprays from Spiraea × arguta which is in full glory in the garden right now.
They work well together in a vase

and look fresh today (unlike a little piece of Aubrieta which I added to the posy last night).
They both have very tiny flowers, but in profusion, and their individual flowers are very similar in size.
On close inspection, the forget-me-not flowers has it for sheer beauty. Its a delicate blue, with a lovely little yellow centre. Some of the little flowers are pink with yellow centre.
In your book, is it a flower or a weed?
In the garden they are (in height) about 20cms and 120cms respectively but I'm thinking that the forget-me-not would be perfect planted (or in my case allowed to self seed) around the perimeter of the Spirea.
Heres a challenge to our camera fanatics. How about a nice photo of both?