Question about The wild mission

Been stuck on this map for a while now, not really sure what to do at this point. Right now I've circled the map and killed pretty much everything that's in my area, but there's a part I can't reach which has a stone on the ground with bluish glowing signs. If I remember correctly from the cinematic you had to grab a seed and put it on the ground, but I checked the plant where you get the seed from and it's empty. Did I miss something or do something wrong?

Remember those two centaurs that you saw earlier in the mission? They start talking and drop a vine seed to use to open up that bridge. It is for the bonus part of the mission, if you killed them before they were done talking, you cant' get to the bonus.

EDIT: nm , I think I got it, sorry for the hassle.