Abstract: A clamp for fixing a plant stem to a support wire includes a movable clamp member, a fixed clamp member, a support shaft and a spring attached to the movable and fixed clamp members. Each of the movable and fixed clamp members has a semicircular beak at its one end and an operating member at its other end. The fixed clamp member has an intermediate body portion provided with a support slot for accommodating an intermediate portion of the movable clamp member. The support shaft pivotally attaches the intermediate portion accommodated in the support slot to the fixed clamp member. The spring applies a biasing force causing the two beaks to close onto each other in the manner of a ring and the two operating members to open in a V-like manner. The body portion is provided with slits extending part way along the floor of the support slot from the beak in the direction of the operating member.