The airplane was landing at the destination airport in gusty wind conditions. The commercial pilot reported that wind was aligned predominately down the runway with gusts approximately 10 knots above the steady state winds. When in the flare to land, the airplane would not settle to the runway normally. The pilot held the landing attitude and waited for the airplane to touch down. When the airplane floated past the pilot's planned touchdown zone, the pilot initiated a go-around. When the pilot selected full throttle and set a pitch attitude for the climb out, the airplane's stall warning horn came on. The pilot lowered the pitch and retracted wing flaps from 40 degrees to approximately 20 degrees. The airplane stalled, and the left wing and propeller contacted the runway. The airplane departed the left side of the runway and came to rest in an upright position. An examination of the airplane following the accident revealed that the left wing near the wing tip was bent upward and the firewall was buckled.