Zaatar comes in many varieties in Lebanon; heard from a couple of sources that the total count was in excess of 133! The one above is called green (akhdar), and gets foraged and used in salads. The equivalent could be wild savory. It is pungent and good with grilled meat as well. Chef Mattar has a recipe in which she makes a pesto out of it. Real good.
The difference between this zaatar and the one that ends up as a mix with sumac and sesame seeds, is this one is either consumed fresh or gets pickled; the pickles can be found at the Middle-Eastern grocers in the US; pickled zaatar is good added to a feta or labneh salad or mixed as a condiment with other foods.
The salad here is very traditional and typical of village food.
This zaatar bush above is for the variety that ends up as a dry mix.