Its name was chosen in honor of the grower Van Hood. At first glance, very similar to cactaceae due to their densely ribbed and spiny stems, they have assumed this aspect to adapt to survive the original desert environments, storing water in the fleshy stems and presenting themselves full of quills, instead of leaves, to keep it as much as possible: this adaptation has made them extremely resistant, both to heat and frost! H. pilifera has a fleshy stem of greyish green color, equipped with protruding tubercles and thorns. Its name comes from Latin and the term "pilifera" means "hair" thanks to the similarity of its thin and flexible thorns, with the hair. The flowering period is August-September, but the flowers bloom when the plant reaches a mature age: for this it normally takes about 5 years. Its beautiful flowers have a flat shape and colors ranging from dark purple to brown, almost black.