Za'atar is the name of both the wild thyme (Origanum syriaca) that is native to Palestine, Jordan, and the surrounding areas, and it is also the name for the tangy lemony spice blend containing the herb, along with sumac, sesame seeds and salt. Most recipes for Za'atar in the United States call for using thyme, but I sought out and grew the original wild plant, which has a flavor with hints of thyme, oregano and marjoram.