A flexible rotary cutting device useful for attaching to a rotary drive configured to trim vegetation, particularly a lawn mower. The flexible rotary cutting device includes a cutting head, an attachment mechanism, at least one cutting-filament retention mechanisms, and at least one cutting-filament. At least one cutting-filament may be releasably attached to the at least one cutting-filament retention mechanism. The at least one cutting-filament may be configured to sever vegetation as the cutting head is rotated, and may be positioned such that it is passed through the at least one filament-aperture, and between the first-filament engaging pawl and the second-filament engaging pawl, in such a way that the at least one cutting-filament is engaged and anchored by the first-plurality of teeth and the second-plurality of teeth, and extends radially from the outer flange of the cutting head.