Alcea is the genus name for a group of flowering plants that typically is grown across Europe, Asia, and North America. Although many people know Alcea by its common name "hollyhock," it is also called althaea, malva flower, or mallow. These plants are popular in gardens because of their large, brightly colored blooms and are particularly useful when attempting to achieve an English garden effect. In addition, some people use the various parts of the plants, including the stems, leaves, roots, and flowers, for medicinal purposes.
Typically, Alcea plants grow anywhere from 5 feet (about 1.52 m) to 8 feet (about 2.44 m) in height. Multiple blossoms usually grow on the tall stalks, ranging in color from pink or red to yellow or white. The blossoms themselves can reach 5 inches (about 12.7 cm) in diameter. Most species grow best in full sunlight and away from strong winds. In addition, the plants are usually quite tolerant to both cold and heat. Some species, such as Alcea rosea can survive even if the temperatures dip to -50°F (about -45.6°C).
Some species, including Alcea rosea, also are more likely to develop diseases or become hosts to pests. As a result, some plants may appear tattered, especially if affected by spider mites, rust, Japanese beetles, or leaf spot. Other species, such as Alcea ficifolia, are less likely to develop pests or disease, which can make them easier to grow. Alcea rogosa, a species with brilliant yellow blossoms that is native to Russia, is another species that typically has less risk of developing disease or pests.
While many people grow Alcea plants for their aesthetic effects, others grow them for their medicinal uses. Interestingly, nearly all parts of the plants may be used, including the blossoms, seeds, roots, stems, and leaves. Specifically, the plants are believed to help with digestion and respiratory problems. Some people think that drinking tea made from these plants will help break up the mucus in the lungs. In addition, plant extracts often are used topically for areas where ulcers or inflammation is present.
When using Alcea plants for medicinal uses, it is important to use specimens that are free of both disease and pests. It also is important to note that medical research has not been completed to indicate whether or not the plants are safe for consumption. As a result, women who are pregnant or nursing or people who have health problems should consult a medical doctor before using it.