The part of the cauliflower that is eaten is the immature flower head of the plant. Cauliflower is harvested by cutting 1-2 inches of the stem below the base when the head reaches six or more inches in diameter. The stalk and leaves around the head are removed before cooking.
Also called "curds," the heads of the cauliflower plant are blanched during the growing process by wrapping and securing leaves around the flower heads in an effort to preserve the white color and enjoyable flavor. Some species of cauliflower do not need blanching and come in shades of orange, purple, or green.