Calceolaria is a shrub-type plant of the Scrophulariaceae group with flowers that are shaped like the toe of a slipper or a purse. Due to the shape of the flowers, it is also known by the name pocketbook plant or slipper plant. The calceolaria family covers a large group of soft-stem plants, which vary greatly in height—they can be as tall as 3 feet (1 meter) or as short as 6 inches (15 cm). The color of the flowers is usually orange or yellow, though newer hybrids sometimes are multi-colored. It is generally very difficult to grow and cultivate these plants outdoors, and for this reason, the calceolaria is primarily found in greenhouses or on the estates of those wealthy enough to hire a full-time gardener.
The calceolaria is an annual, which means that it generally must be replanted every year. In some cases with near-perfect weather conditions, a seedling may come back independently without replanting, but this is rare. Throughout their yearlong growth cycle, this plant needs constant attention, as it cannot survive excessive heat, frost, or sun. The plants are native to South America, though today they can be found in gardens and greenhouses in North America and Europe as well.
These tropical flowers cannot survive temperatures below 45 degrees Fahrenheit (7 degrees Celsius), so outdoor planting should be done in April or May when all danger of frost has passed. Moist soil with optimum drainage and a location that receives at least partial sun are generally necessary for a healthy, thriving plant. If growing the calceolaria inside the home or in a greenhouse, a soil mixture of humus and loam should generally be used, and the new plants should be placed in an area that receives good ventilation. According to most experts, fertilizer should not be applied until there is a well-established root system.
Pests that often attack the calceolaria are spider mites, whiteflies, and aphids. The spider mites are attracted to low humidity, so keeping the plants moist is a one means of prevention. Whiteflies often leave a black fungus on the plant, so their infestation is quite easy to detect and can be eliminated with pesticides. Aphids are usually not as harmful to the calceolaria as spider mites and whiteflies, and they can also be controlled with pesticides.
In South America, studies are currently underway to determine if there is a medicinal value to the plant. Some scientists believe that it may contain properties that are beneficial to digestion and stomach irritation. There is also some indication that it may offer anti-bacterial protection.