卜 is one of the oldest Chinese characters — it depicts the cracks in heated oracle bones used for divination in the Shang Dynasty (1600-1046 BC). The vertical stroke is the bone, the short stroke is the crack.
usage
As a surname, 卜 is pronounced bǔ. It appears in the common word 萝卜 (luóbo, radish), where it's pronounced bo with a neutral tone.
