a thermoplastic container obtained by blow - molding of a preform , with a base including in its central part a multiple - branch cross - shaped impression provided with a central recess from which radial branches radiate ; the base is of the petal - shaped type with at least three legs formed by protuberances located near the periphery ; there are as many legs as branches mutually aligned radially ; each leg includes a notch for absorbing stresses radially separated from the end of the respective branch .