The machine has a frame (1) and a collecting device (2) for collection of plants on the ground. A processing device (3) processes the plants. A set of connection units (25, 26) is geometrically and/or elastically configured such that a frontal lower end (49) is strongly raised above the ground and an intermediate part (52) is brought closer to points of teeth (9) of the collecting device in one position, and the lower frontal end is brought closer to the ground and the intermediate part and a rear portion (50) are far away from the teeth points in another position of connection units.
