A seeder including a chassis including a substantially horizontal transverse beam on which seeding elements are distributed in a regular manner, the transverse beam including a central section and two lateral sections arranged on either side of the central section in a work position, and being raised substantially above the central section in a transport position, each lateral section being connected to the chassis by a respective arm and being displaceable transversely and vertically with respect to the chassis by a deformable mechanism controlled by an operating jack. In the seeder one deformable mechanism is offset with respect to the other deformable mechanism, taking into account a direction of advance.