Frailea is a genus of cactus native to South America. It is named for Spanish scientist Manual Fraile, who made important contributions to the study of cacti while working for the US Department of Agriculture in the early 20th century. The frailea genus consists of many species, though each shares a small, globular form. Most types of plants within the frailea genus grow best in sandy or loamy soil, and all thrive in hot, humid climates. These cylindrical cacti are often found in mountainous regions, where they sprout up among rocky surfaces.
One of the most distinctive features of the frailea plant is its ability to self-pollinate. While these plants are capable of producing brilliant flowers, they often release seeds without producing a bloom. The seeds begin to grow around the plant, often before the gardener is aware the plant has sprouted. Because of this, frailea often grow in clusters, and can be difficult to plan in a controlled environment. When flowers are visible, it is often only during the hottest part of the day when sun levels are at their highest.
The frailea cataphracta is one of the most popular species of this plant. Known for its round, squat shape, this plant is among the largest of the frailea genus. It features a ridged and lined surface that gives it an appearance similar to the bottom of an artichoke. The plant is primarily green in color, but develops shades of purple and brown as it ages and develops. When the cataphracta does bloom on hot days, it may produce a flower larger than the plant itself, with blooms ranging from white to yellow in color.
Frailea castanea is another popular species within this genus of cacti, and is known for its chestnut brown coloring. It has a very distinct appearance that resembles a squat pumpkin, with vertical grooves running up and down its base. Groups of chocolate brown spines are centered along each vertical section between the grooves. These stems are arranged in clusters to give the plant a button-like pattern. Like all plants in this genus, the castanea rarely shows its blooms.
Frailea pygmea is a form of dwarf cactus that are often found in the same area as the castanea plants. The pygmea species closely resembles a pineapple, with a cylindrical base and tall white or yellow flower centered on top. The base of the pygmea may lie partially underground, with only the flowering portion visible. The entire base is covered by soft yellow spines that give this species a wool-like appearance.