This is a variable species, but the photograph is a good representation of what they should look like. Even the number of ribs can vary, but usually there are five to seven. The plant branches, both from the base and also higher up the stems. The body is a strong slate blue with whitish areoles that are covered in brownish yellow spines running continuously up the ribs of the plant. There are normally 10-14 radial spines and six to eight central which are slightly longer than the radials. They are so close together that they look like a continuous dense brown line. When the plant is old enough it will produce a pseudocephalium. Plants can easily get to 6-10ft. tall.

Growing Conditions
Light: Like most cacti, they need lots and lots of direct sunlight to flourish
Water: Weekly watering should be sufficient for their water needs: they need a solid supply of water during the summer; make sure not to overwater them, which can cause rot
Temperature: Hot tropical temperatures, ideally around and above 70 degrees
Soil: Pilosocereus plants like a dry soil with some organic material, and good drainage is essential
Fertilizer: Complementing their water with a diluted liquid fertilizer once every few weeks during the growing season will help; use a balanced fertilizer like a 20-20-20.

Grower’s Tips
These are vigorous, fast-growing cacti that need regular water and fertilizer to reach their full potential. Make sure to keep them in a warm place in winter and plant them in a place with lots of space, because these columnar cacti will eventually grow to be quite large. Alos, make sure their soil drains well—poor drainage is a death sentence for most cacti. P. pachycladus is particularly known as an easy, forgiving cactus that can flourish with only minimal help from you, and most tropical gardeners shouldn’t have trouble with them.