Pilosocereus is a genus of columnar cacti native to arid areas of Mexico, the West Indies, and South America. They may be grown by gardeners outdoors in arid landscapes, or indoors if residing in a cold climate. Some species of Pilosocereus, such as the Pilosocereus fulvilanatus, are threatened by extinction in the wild.
The genus Pilosocereus includes about 50 different species of cacti. All Pilosocereus cacti are columnar shaped, meaning they grow into a tall, upright, cylinder shape resembling a column. Often times these plants will produce funnel shaped flowers that open at night and remain in bloom for less than 24 hours. The flowers are generally large, produce a strong scent, and may come in a variety of colors from blue, yellow and white.
The native range of Pilosocereus is wide. They originate in Mexico, the West Indies, and into South America, especially Brazil. Yet these plants have been cultivated elsewhere, especially in arid regions of the United States.
For these plants to survive, they must be kept in a warm, arid environment. They can only be cultivated outside if in a desert environment where frost rarely occurs. Pilosocereus cacti need to be protected from even the mildest frosts. Some gardeners recommend that if frost is expected, paper or plastic drinking cups can be placed on the tops of the stems of the cactus in hopes that the most fragile part of the plant may be protected. They can also be grown in pots that are either kept indoors all year round or left outside during the summer. It should be noted that if grown in pots, these plants may not reach their full height.
Since Pilosocereus cacti are desert plants they do not need a lot of water and overwatering may actually cause them harm. The area most Pilosocereus originate from experiences a dry season between November and May, and a wet season from May to October. Some gardeners suggest that because of this trend, these plants should be watered regularly in late spring and early fall, and watering should be much less during the rest of the year.
There are some species of Pilosocereus that are threatened. One example is the Pilosocereus fulvilanatus, which is native to arid areas of eastern Brazil. The native environment of this cactus has been largely destroyed through cultivation of farm land and also by conversion of land for charcoal production. The only Pilosocereus fulvilanatus still surviving in the wild reside in rocky areas inappropriate for use by humans. Although rare in the wild, this plant is often grown in nurseries, botanical gardens, and by private gardeners.