An agricultural machine for harvesting a crop, which is equipped with a harvesting head, includes: a mowing bar for harvesting the crop； at least one transportation system adapted to transport the crop cut by the mowing bar to a collection mouth of the harvesting head. The at least one transportation system includes: a first transmission system having a first flexible element coupled with a pair of first rotary elements； a second transmission system having a second flexible element coupled with a pair of second rotary elements； at least one arm coupled with both of the first flexible element and the second flexible element, in such a way as to extend on the harvesting head substantially transversally relative to the mowing bar both during a transportation step for transporting the crop cut by the mowing bar and during a return step.
