found it in some gifted black eyed susans, thought the broad leaves looked like some kind of mum but the more it grows the more I wonder what I am growing.

Do the leaves have a particular odor when crushed?

porkpal said:Do the leaves have a particular odor when crushed?

never thought of that but yes , sort of a faint citrusy rosemary or thyme smell to me

This is just a guess. Could it be Artemisia vulgaris/Mugwort?

greene said:This is just a guess. Could it be Artemisia vulgaris/Mugwort?

could be , think it is definitely mugwort

I've been wondering what it is; it grows in our pastures.

I was only guessing.
This morning I looked online to check if my guess was correct and I found this:
http://identifythatplant.com/i...
Kroba, how does your plant compare to the photos in the link?

greene said:I was only guessing.

I believe you nailed it Greene , I am 99.9% positive it is Artemisia vulgaris (mugwort) and more importantly happy with your identifying "guess" , for your much appreciated assistance. Not sure I plan to keep it , but will most likely see what it will do in the little pot I have it in for now.

You can pick and dry the herb to make a dream pillow.