Asafoetida has a pungent smell, as reflected in its name, lending it the fennel vs celery name of “stinking gum”. Its pungent odour has resulted in its being known by many unpleasant names. Other names for it include ting and haltit or tyib in Arabic, and hingu in Malay.

Many Ferula species are utilized as the sources of asafoetida. Most of them are characterized by abundant sulfur-containing compounds in the essential oil. Ferula assa-foetida is endemic to Southern Iran and is the source of asafoetida there. It has sulfur-containing compounds in the essential oil. Ferula pseudalliacea and Ferula rubricaulis endemic to western and southwestern Iran are sometimes considered conspecific with F. Ferula lutensis is the source of asafoetida in Eastern Iran.

Ferula alliacea is the source of asafoetida in Eastern Iran. Ferula latisecta is the source of asafoetida in Eastern Iran and southern Turkmenistan. Ferula sinkiangensis is endemic to Xinjiang, China. It is the source of asafoetida in China.

Ferula fukanensis is endemic to Xinjiang, China. Ferula narthex is native to Afghanistan, northern Pakistan and Kashmir. Although it is often listed as the source of asafoetida, one report stated that it lacked sulfur-containing compounds in the essential oil. This spice is used as a digestive aid, in food as a condiment, and in pickling. It plays a critical flavoring role in South Asian vegetarian cuisine by acting as a savory enhancer.

In its pure form, it is sold in the form of chunks of resin, small quantities of which are scraped off for use. The odor of the pure resin is so strong that the pungent smell will contaminate other spices stored nearby if it is not stored in an airtight container. The resin-like gum comes from the dried sap extracted from the stem and roots, and is used as a spice. The resin is greyish-white when fresh, but dries to a dark amber colour.