This plant uses its tentacle-like vines to strangle it's prey, not unlike a snake.
In escaping the Devil's Snare, expose some light upon the plant. It will shrivel and recoil from the light. Casing any lumos spell, or even shining a torch, will cause the Snare to release you.
(Image by thepolestar. Devil's Snare is the creation of J.K. Rowling).