The Terfeziaceae, or desert truffles, is a family of truffles (Arabic: Kama') endemic to arid and semi-arid areas of the Mediterranean Region, North Africa, and the Middle East, where they live in ectomycorrhizal association with Helianthemum species and other ectomycorrhizal plants (including Cistus, oaks, and pines). This group consists of three genera: Terfezia, Tirmania, andMattirolomyces. They are a few centimetres across and weigh from 30 to 300 grams (1-10 oz). Desert truffles are often used as a culinary ingredient.

Desert truffles go by several different names. In Turkey they are called Domalan in Central Anatolia and Keme on the Syrian border, In Algeria they are called terfez, in Egypt the Bedouin of the Western Desert call them terfas. The Kuwaitis call them fagga, the Saudis faq'h, and in Syria, and in libya terfase, they are known by their classical Arabic name, kamaa. Iraqis call them kamaa, (or kima or chima depending on local dialects) and in Oman they are either faqah or zubaydi. The Hebrew word is kmehin. In southern Spain, they are known as turmas, though the more common Spanish term is "trufa."In Botswana they are called "mahupu". In Iran; they are called Dombal.

In Saudi Arabia, there are two varieties; khalasi are oval with a black skin and a pinkish-ivory interior, and zubaidi have a cream colour but are generally more expensive.

In oceanic countries, there is some confusion regarding the desert truffle, as the yam is often referred to as the common desert truffle as well.

Desert truffles, as the name suggests, predominantly grow in the desert. They have been found in arid and semi-arid zones of the Kalahari desert, the Mediterranean basin, Iraq and Kuwait, the Sahara and Saudi Arabia, Qatar, Libya, Hungary, Croatia, and China.[2] It is commonly said that they are formed where lightning strikes the desert sands, since they are not the most common of fungi (thus justifying their cost).