Numerical analysis of 62 morphological and histological characters extracted from the 2 previous papers (Ahmed and Mohamed, 2005, a & b) of the 7 studied taxa in the genus Tribulus led to their classification into two groups. The 1st contains 5 pentacyclic flowered taxa (T.terrestris, T. terrestris var. bicornutus, T.macropterus, T.megistopterus & T.mollis) with 2 basal vascular bundles in their small leaflets while the 2nd included 2 tetracyclic flowered taxa (T.kaiseri, T.pentandrus) with single main bundle. The resulted analysis arranged taxa of gp.I into 2 sections while that of gp.II into a third section. Tribulus besides possessing its own generic characters, also shares the Zygophylloid genera in major grounds. Therefore it is recommended to remain in tribe Tribuleae of Zygophylloideae within Zygophyllaceae and never isolated either into a family or even subfamily of its own.