The Terfeziaceae, or desert truffles, is a family of truffles 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, and Mattirolomyces. They are a few centimetres across and weigh from 30 to 300 grams (1-10 oz). They are often used as a culinary ingredient, although due to their rarity they are very expensive.
Desert truffles do not have the same flavour as European truffles, but tend to be more common and thus more affordable. Whereas forest truffles typically cost $100 per kilogram, and Italian truffles may sell for up to $2200 per kilogram, desert truffles have been sold in Riyadh for $26.75 per kilogram. (Prices in 2002 US Dollars)
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.