This slow-growing columnar and erect cactus boasts numerous unbranched stems and can grow up to twenty feet or more in its native habitat. Only the radial spines are visible on its stem, which is covered in woolly grayish-white hairs that resemble an old man's facial hair; it is also known to have survived for over 200 years. These distinct grayish-white hairs serve a dual purpose. In scorching summers, they shield the young cactus from blistering temperatures while providing snug warmth during chilly winters.
