These are tightly closed Argentine Cactus flower buds. The buds open to a full bloom only during the night. When in full bloom, the flowers are about the size of an adult's open palm and fingers. The blossoms last only for about a day before they wilt and fall away. The buds are a favorite munchie for Sonoran Desert Javelinas that will gobble them up before they have a chance to bloom. The natural light was filtering in through the leaves of a nearby tree creating a moody spotlight effect against the shaded background..