The Terfeziaceae, or desert truffles, is a family of truffles (Berber languages: script=latn|Tirfas, Arabic: كمأ|Kam', Kurdish: دۆمبەڵان|Dombelan, Hebrew: כמהת הנגב|kmehat hanegev) 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). Desert truffles are often used as a culinary ingredient.
Fruit-bodies (ascomata) are large, more or less spherical to turbinate (top-shaped), thick-walled, and solid. The asci are formed in marbled veins interspersed with sterile tissue. The asci are cylindrical to spherical, indehiscent (not splitting open at maturity), and sometimes stain blue in iodine. Ascospores are hyaline to pale brown, spherical, and uninucleate.[1]
Desert truffles have been found in arid and semi-arid zones of the Kalahari desert, the Mediterranean basin, Syria, Azerbaijan, Iran, Iraq, Kuwait, the Negev desert in Israel, the Sahara, Saudi Arabia, Qatar, Libya, Spain, Greece, Cyprus, Hungary, Croatia, and China.[5] [6] As the name suggests, they predominantly grow in the desert. They can be formed near Sunrose (Helianthemum) plants, but they are very rare to find and cannot be cultivated (justifying their cost).
Desert truffles do not have the same flavor as European truffles, but tend to be more common and thus more affordable. Forest truffles (genus Tuber) typically cost $1,000 per kilogram; Italian truffles may sell for up to $2,200 per kg, while Terfezia truffles sold as of 2002 in Riyadh for $200 to $305 a kg, and in recent years have reached, but not yet exceeded, $570. Israeli agricultural scientists have been attempting to domesticate Terfezia boudieri into a commercial crop.[7]
Desert truffles go by several different names. In Iran they are called Donbalan or . In Turkish they are called in Turkiye, also Keme on the Syrian-Turkiye border. In Algeria and Tunisia they are called ; the Bedouin of the Western Desert call them terfas ترفاس. The Kuwaitis call them Arabic: فقع, the Saudis Arabic: فقع, and in Syria, and in Libya Arabic: ترفاس; they are known by their classical Arabic name, Arabic: كمأ. Iraqis call them , or Arabic: كمأ, depending on local dialects and in Oman they are Arabic: فقع. The Hebrew word is כמהין (in singular). In Catalonia they are known as and . In southern Spain, they are known as or and in the Canary Islands they are known as . In Botswana they are called mahupu. In Hungary they are known as ('sand truffles') and are sold to English-speaking nations as honey truffles.[8]
In Saudi Arabia, there are two varieties; are oval with a black skin and a pinkish-ivory interior, and 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.[9]