Abstract: A blade for a rotary mower, in particular lawnmowers, with a cup-like downward open cover (21) for the seating of the blade (1) presenting two sails (4, 4') that are provided on their front longitudinal edges (5, 5') in the direction of rotation with cutting edges (6, 6). The cutting edges of the blade sails of the blade according to the present invention constitute several cutting planes, whereby the outer cutting edge section (8) within the region of the sail extremities is located below the plane of the blade's hub portion (3). To this outer cutting edge section (8, 8') is attached a central cutting edge section (10, 10') that curves above the plane of the hub portion (3) and changes over to an inner cutting edge section (13, 13') that drops off toward the hub portion (3).