Devices and methods are disclosed which provide for harvesting hair follicular units, including severing any remaining connective tissue strands during the harvesting process, so that the harvested follicular units are retained in the harvesting tool without being damaged. The devices and methods of the present invention are especially useful with the partially or substantially automated systems and methods for hair harvesting and transplantation. The follicular unit harvesting tools may comprise a harvesting cannula and a grasping device moveable relative to each other.