The most widespread species (highest incidence) was Carduus pycnocephalus, followed by Senecio glaucus, Picris babylonica, Plantago boissieri, Koelpinia linearis and Arnebia decumbens. In the control plots,the mostfrequent species was Stipa capensis, followed by Plantago boissieri, Senecio glaucus and Picris babylonica.