Ascomata: hypogeous to partially emergent at maturity, 3–12 cm in size, subglobose, turbinate, obpyriform, sometimes gibbous, lobed, irregular in form, often with tapered, sterile base, ochre-salmon at first, becoming reddish brown, blackening with age, initially smooth, but often furrowed, associated with rapid growth.
Peridium: 1–1,5(–3) mm thick, whitish pink in cross section, composed of thin-walled hyphae, 8–20 µm broad at septa, appearing as parallel hyphae or as more or less rounded elements, depending on the section angle, hyalines in the innermost layers, yellowish and with thicker walls in the outermost layers.
Gleba: solid, fleshy, succulent, whitish to pale pink at first, maturing to pink salmon pockets of fertile tissue separated by whitish pink, sterile veins, inconspicuous at maturity, sometimes with yellowish brown spots.
Odour: faint, no distinctive.
Taste: mild, pleasant, gastronomically prized.
Countries around the Mediterranean sea and in the Middle East, limited to arid and semiarid areas, in calcareous, clayey or sandy, alkaline soils, associated with Helianthemum spp., March through May in Spain, January through March in in the Middle East and North Africa countries. Its fruiting period is very dependent on rainfall and temperature, absent some years, when weather conditions are not suitable.
Asci: nonamyloid, subglobose to ovoid, pyriform, sessile, 70–100 x 50–70 µm, with 6–8 irregularly disposed spores, randomly arranged in fertile pockets.
Ascospores: globose, (17–)18–21(–23) µm diam (median = 20 µm), including ornament, hyaline, smooth and uniguttulate at first, then yellow and ornamented with rounded, sometimes truncated warts, up to 2 µm tall and 2–3 µm broad at the base, forming an irregular, coarse reticulum, often incomplete, with variable height and thickness of the ridges; sometimes warts are very prominent and reticulum is inconspicuous in the light microscope.
The most distinctive characters of Terfezia claveryi are: big size (some up to 400 g), reddish brown colour, associated with Helianthemum spp. in basic soils, spores ornamented with rounded, sometimes truncated warts, up to 2 µm tall, forming an irregular, more or less evident reticulum, often incomplete.