The cereal culture under centre spindle is of recent creation, it was the object of an establishment in an ecosystem characterized by a natural and typical unprompted flora. The cereal fields, represent a middle to strong pressures which can, with the development of agrarian techniques, lead to answers adapted to the introduced flora that can evolve fast in an intrusive flora. However, unprompted kinds, who must have developed strategies to survive and reproduce in frustration especially of the use of pesticides, will be systematically destroyed on their middle with as consequence, a threat of disappearing of a flora perfectly adapted to Saharan conditions.\r\nFor it and in a purpose to update the inventory of the plants of the cereal fields and have a knowledge on their biology, ecology and sharing out for the region of Ouargla, as well as to put in an obvious place the impact of different agrarian practices on the unprompted flora, taking into account of its permanence, we performed a job which concerned the inventory of the complete flora of three experimental stations kept for their ages of bet in culture. Inventory, allowed to bring to light, a comparatively rich accidental flora in cash, characterized by the dominance of the introduced messicoles provided principally by Poaceae, characteristic family, par excellence, of the accidental flora of the cereal fields in our region of study.\r\nThe parameter age of bet in culture had a significant effect on composition, in cash introduced and unprompted, of the complete accidental flora of the experimental stations. They attend a phenomenon of impoverishment of the typical unprompted flora and an enrichment accentuated in the time of the messicole introduced flora which became more and more intrusive.\r\nKey words: Flora messicole, introduced flora, unprompted flora, diversity, dominance, cereal culture under centre spindle, Algeria.
Author(s): Sayed Ibtissem, Hamid Cheloufi, Omar Eddoud