TRAGACANTH (Heb. נְכֹאת, nekhot). The identification of tragacanth with nekhot is attested by its Arabic name Rathirā ʾ. It was included in spices carried by the caravan of Ishmaelites from Gilead on their journey to Egypt (Gen. 37:25), as well as in the gift sent by Jacob to the ruler of Egypt (43:11). It is the aromatic sap of a species of Astragalus which is called τραγακανδα in Greek. These are plants of the family Papilionaceae, short prickly shrubs which exude a sap when the roots or stalks are split open. Tens of species of Astragalus grow in Israel but these do not exude the nekhot. This is obtained from the species that grow in east Asia and the mountains of Syria and Lebanon. In former times it was used as incense but today it is used for medicinal purposes.
Loew, Flora, 2 (1924), 419ff.; J. Feliks, Olam ha-Ẓome'aḥ ha-Mikra'i (19682), 274–5.