Cephalocereus Senilis or most commonly known as Old Man Cactus, is one of the most popular and identifiable Cactus members. The fine white hairs cover the entire fleshy columnar body and hide the sharp spines. Aside from its charm, the hair serves an important purpose. It protects against the harsh desert sun common to this plant's native home.
Allow the soil to dry out completely before watering. Overwatering is the most common death sentence for cactuses.