Hi,
This plant has come out in my yard this spring. I don't think I had ever seen it in my garden before. It looks like poison hemlock, but I am not sure since it doesn't have any purple spots on its stems. Any ideas on what it could be? And do you think I should keep it?

Maybe Queen Anne's Lace.

Poison Hemlock has purple markings on the stems; sometimes faint and sometimes very visible. For comparison: Poison Hemlock (Conium maculatum)



Queen Anne's Lace has no purple stem markings. For comparison: Queen Anne's Lace (Daucus carota)

I don't know what it is, these umbelliferous plants can be hard to identify, other than that it isn't Queen Anne's Lace because there are no bracts under the flower heads.

The OP lives in Turkey. Might it be one of the plants we call sweet cicely? Myrrhis odorata

Do the bruised leaves have any particular odor?

I just crushed and smelled a couple of leaves. The smell is a bit sharp but not so bad. It resembles the scent of fresh cut grass.

Here are a few other photos of the plant. Any thoughts?