Tribulus terrestris var. robustus (Boiss. & Noe) Boiss.
Annual or biennial, prostrate, densely appressed whitish silky pubescent herb. Stem hirsute to sericeous, branches spreading. Leaves paripinnate, 2.5-5 cm long; stipules lanceolate to falcate, 3-5 mm long; leaflets (4-) 5-6(-8) pairs ovate to elliptic-oblong, 5-10(-12) mm long, 3-8 mm broad, inequilateral, acute. Flowers yellow, 1-1.5 cm across; pedical up to 1.5(-2) cm long. Sepals ovate-lanceolate, 5-6 mm long, c. 3 mm broad, acute. Petals obovate, 6-8 mm long, 3-4 mm broad, obtuse. Stamens 10, filaments c. 3-5 mm long, anthers versatile. Ovary ovoid, hirsute; style c. 1.5 mm long, stigmas decurrent. Fruit up to c. 1 cm in diameter, 4-8 mm long, mericarps densely crested and tuberculate on dorsal side, densely hairy to glabrescent, with 2 long patent and 2 short downwardly directed spines (rarely all or lower 2 reduced to tubercles).
Fl.Per.: Almost throughout the year.
Type: Described from South Europe.
Distribution: Tropical and subtropical countries in Asia, Africa, S. Europe, North Australia and introduced in new world tropics.
Common throughout Pakistan from sea level to 3500 m, in sandy soils of barren lands and cultivated fields as a weed.
A highly variable species in leaf and flower size and fruit characters. Many authors recognize subspecies and varieties on the basis of presence or absence of spines, tubercles and indumentum on the dorsal side of mericarps but these characters do not seem constant and correlated and I prefer to recognize one variable species without any formal infra-specific taxa.
The plant is used as a diuretic, demulcent, tonic, aphrodisiac and aperient. The fruit is used in painful micturition, urinary diseases, impotence, cough and heart diseases.