Looks like a Sedge species.

Thank you but please be more specific. The roots and seeds tell a lot when zoom in. Can I rule out that it's "not" Green kyllinga , which far away looks very similar?

Looks like Kyllinga to me. I would not try to separate the species from a photo.

'Thank you but please be more specific' If I could have been more specific I would have been. I was just trying to start you off with an area to research. If you already knew it was a sedge it would have been helpful to say so in your heading so I wasn't misled into making a suggestion.

I have that same weed and the product Sedge Ender has been very effective in controling it with about 2 applications a year. It has also helped a great deal with nut sedge in a rose garden.

@floral. I didn't know for sure. At first I tought it was yellow nutsedge but unsure that' s why I wanted to confirm.

After 2 days of research I found a great tool to properly ID weeds. With that tool the search it gives says my weed is:

Green Kyllinga

(Kyllinga brevifolia

the tool said that sedge family has triangular shape seeds and my weed seed head is round so Im thinking its kylinga..do you agree?

here s the tool

http://www.weedalert.com/byname.php