Asafoetida (/æsəˈfɛtɪdə/; also spelled asafetida) is the dried latex (gum oleoresin) exuded from the rhizome or tap root of several species of Ferula, perennial herbs growing 1 to 1.5 m (3.3 to 4.9 ft) tall. They are part of the celery family, Umbelliferae. Asafoetida is thought to be in the same genus as silphium, a North African plant now believed to be extinct, and was used as a cheaper substitute for that historically important herb from classical antiquity. The species are native to the deserts of Iran and mountains of Afghanistan where substantial amounts are grown.