WASHINGTON (AP) -- Rep. Gabrielle Giffords has resigned from the House with a standing ovation from her colleagues, more than a year after she was gravely wounded by a would-be assassin.

The Arizona congresswoman formally resigned after a series of tributes from her colleagues. She's stepping down to focus on her recovery from a gunshot wound to the head.

As Giffords sat in the chamber's front row, lawmakers praised her dignity, grace and perseverance. Her mother, Gloria, and husband, retired Navy Capt. Mark Kelly, watched from the gallery. Giffords stood in the well of the House as her close friend, Rep. Debbie Wasserman Schultz, read her resignation letter. Other members of the Arizona delegation surrounded her. And Rep. Jeff Flake held her hand. An emotional Wasserman Schultz said Giffords would return one day.