Although this cactus reminds me of a stick of cotton candy that’s been stuck full of toothpicks, it is actually an Espostoa melanostele, a columnar cactus native to the Andes of Peru. The white wooly spines look like a mat of hair, and the longer, sharp central spines protrude from the wool. One purpose served by the wooly spines and long central spines is to act as a water collection system after a rain. The wooly spines collect moisture and the long central spines collect droplets of water that then drip down from the spines to the shallow roots. The wooly spines also act as protection from sunburn.
The E. melanostele is very rot prone, so planting in well-draining soil is necessary. It is also cold sensitive, and won’t take temperatures under 50˚. Other than these few caveats, it is an easy to grow potted cactus. It won't do well in the ground in a desert garden because our winter nights can occasionally reach into the 20s and 30s Fahrenheit. In habitat it will grow to seven feet tall.
There are 16 species in the Espostoa genus. After 10 to 30 years in age, they reach flowering size. At that point, a thick beard of white wool grows on one side of the upper stem, and from this beard, stinky flowers appear, followed by red berries. Though this doesn’t happen often in cultivation, I’ve seen this process at our local Desert Botanical Garden. It is quite a sight (and smell!)
Several species of Espostoa are frequently entered into Cactus and Succulent Society shows because of the wooly spines, which are popular with the crowds. Some exhibitors go so far as to shampoo and then blow dry the wool so that it is clean, fluffy and white. In the last show I attended, a Peruvian Old Man Cactus (E. lanata) had the beauty treatment, and it won a blue ribbon. Obviously, pampering pays off!