Majorana syriaca (L.) Raf.
Origanum syriacum; syn. Majorana syriaca (also Origanum maru, although this primarily refers to a hybrid of O. syriacum), bible hyssop, Biblical-hyssop, Lebanese oregano or Syrian oregano, is an aromatic perennial herb in the mint family, Lamiaceae. It is a preferred primary ingredient in the spice mixture za'atar, and the plant may also be called za'atar. So precious is this herb that in the Levant, Arabs will send out foraging parties to gather it. In Modern Hebrew, it is called ezov, and it may have been the ezov of Classical Hebrew. In many English translations of the Bible, ezov is rendered as hyssop, hence the common name bible hyssop. However, in English, hyssop generally refers to a different plant. Origanum syriacum is native to the Middle East.
Origanum syriacum is harvested in the wild for use in preparing za'atar, although it has recently entered cultivation due to high levels of demand.
In Egypt, Origanum syriacum subsp. sinaicum is a very rare plant grown on stony grounds in Sinai Peninsula including the coastal Mediterranean strip. From the conservation point of view it is an endangered plant. A study of the agronomic and chemical potential of O. syriacum subsp. sinaicum showed that it was superior to O. vulgare subsp. hirtum in herb and oil yields per acre. They also found that the major constituents in the essential oil of O. syriacum subsp. sinaicum was dominated by thymol, gamma-terpinene and p-cymene in a descending manner. 
- "Origanum syriacum". Germplasm Resources Information Network (GRIN). Retrieved 22 April 2013.
- "Origanum syriacum L.". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew. Retrieved 21 April 2013 – via The Plant List.
- "Za'atar, a renowned herb blend, and events inspired by it". Vegetable Gardener. 29 September 2010.
- "Origanum syriacum Bible Hyssop". PFAF Plant Database. Plants For A Future. Retrieved 21 April 2013.
- Based on the Judeo-Arabic translation of the word in the works of Rabbi Saadia Gaon (in his Tafsir, a translation of the Pentateuch, Exo. 12:22), Rabbi Hai Gaon's Mishnah commentary (Seder Taharot), Rabbi Jonah ibn Janah (Sefer HaShorashim - Book of the Roots, s.v. אזב - aleph, zayn, bet), and Maimonides (in his Mishnah Commentary, Nega'im 14:6).
- "Origanum syriacum". Missouri Botanical Garden. Retrieved 21 April 2013.
- Khairallah, Simon (1 January 2010). "Plant story - helping to conserve Origanum syriacum". Kew News. Kew Royal Botanic Gardens. Retrieved 21 April 2013.
- Boulos, Loutfy (2002). Flora of Egypt. Volume 3: Verbenaceae-Compositae. Cairo, Egypt: Al-Hadara Publishing. p. 12. ISBN 9775429250.
- Shalaby, A.S.; Elhefnawy, N.; Ghanem, K.; A. EL-Ghareeb, A. (2011). "Agronomic and Chemical Comparison between Origanum vulgare ssp. hirtum and the Cultivated Plants of O. syriacum ssp. sinaicum". Journal of Essential Oil Bearing Plants (M/s Har Krishan Bhalla & Sons) 14 (4). ISSN 0972-060X. Retrieved 21 April 2013.