Echinopsis pachanoi
The San Pedro cactus is very easy to grow in most areas. Because it grows naturally in the Peruvian Andes Mountains at high altitude and with high rainfall, it can withstand temperatures far below that of many other cacti. It requires fertile, free-draining soil. They average half a meter per year of new growth. They are susceptible to fungal diseases if over-watered, but are not nearly as sensitive as many other cacti, especially in warm weather. They can be sunburned and display a yellowing chlorotic reaction to overexposure to sunlight.
Cactus
Like their spines, cactus flowers are variable. Typically, the ovary is surrounded by material derived from stem or receptacle tissue, forming a structure called a pericarpel. Tissue derived from the petals and sepals continues the pericarpel, forming a composite tube—the whole may be called a floral tube, although strictly speaking only the part furthest from the base is floral in origin. The outside of the tubular structure often has areoles that produce wool and spines. Typically, the tube also has small scale-like bracts, which gradually change into sepal-like and then petal-like structures, so the sepals and petals cannot be clearly differentiated (and hence are often called "tepals"). Some cacti produce floral tubes without wool or spines (e.g. "Gymnocalycium") or completely devoid of any external structures (e.g. "Mammillaria"). Unlike the flowers of other cacti, "Pereskia" flowers may be borne in clusters.