An improved cutter blade or disc mower blade is provided having structure to reduce the tendency of vegetation to slip off and around the blade edge and tip. The disc mower blade is attached to a rotary cutter module and driven by a mowing machine. In one aspect of the disc mower blade, the disc mower blade includes a knife edge with serrations distributed along the edge such that vegetation does not slide along the edge during operation of the mowing machine. Further, another aspect of the mower blade is that the knife edge may be curved so as to prevent the vegetation from sliding along the edge during operation of the mowing machine. In another aspect, the disc mower blade includes a winglet disposed at a tip of the blade such that vegetation cannot slide past the blade during operation of the mowing machine.