Ascomata: hypogeous to partially emergent at maturity, 2–5 cm in size, subglobose, obpyriform, sometimes lobed, often with conical base, sometimes with a basal depression, reddish brown at first, darkening with age, frequent black spots in sun-exposed areas, surface somewhat roughened, often cracked.
Peridium: 0,6–1 mm thick, whitish in cross section, pseudoparenchymatous, composed of subglobose and angular cells, sometimes elongated, 15–40 µm diam, hyalines with walls 1–2 µm thick in the innermost layers, yellowish and with thicker walls in the outermost layers.
Gleba: solid, fleshy, succulent, whitish with pale pink pockets at first, maturing to olive green, blackish gray pockets of fertile tissue separated by whitish, sterile veins.
Odour: faint, no distinctive
Taste: mild, pleasant, gastronomically prized.
Widely distributed in the western half of the Iberian Peninsula, areas with Mediterranean climate, very common in grassland of Extremadura, in acid soils, exclusively associated with Tuberaria guttata, March through April, before than Terfezia arenaria on shallow slate soils . Its fruiting period is very dependent on rainfall and temperature, absent some years, when weather conditions are not suitable
Asci: nonamyloid, subglobose to ellipsoid, ovoid, sessile or short-stipitate, 70–80 x 55–70 µm, wall 1 µm thick, with 6–8 irregularly disposed spores, randomly arranged in fertile pockets.
Ascospores: globose, (18–)19–22(–24) µm diam. including ornament, 14–17(–18) µm diam. without ornament, hyaline, smooth and uniguttulate at first, by maturity yellow ocher and ornamented with conical spines, pointed, straight, separated, (2–)3–4(–5) µm long, 1(–2) µm wide at the base.
The most distinctive characters of Terfezia fanfani are: reddish color ("rojilla" is their popular name in Extremadura), spring season, associated with Tuberaria guttata in acid soils, peridium pseudoparenchymatous, spores ornamented with conical, pointed, straight, separate spines up to 5 µm long