Columnar stems are densely covered in white wool (actually white radial spines that have evolved to resemble "hairs"), that totally obscures body of plant. Some bright red spines are visible above the wool . Flowers are violet red and semi-tubular in shape. Bright light for best appearance. In cultivation, Oreocereus requires bright light to produce dense hairs, but, as a former mountain dweller, does not care for extremely high temperatures. Water thoroughly when soil is dry. Do not overwater during cold winter months. Preferable not to water on overcast days, humid days or cold winter days.