Hibiscus (Hibiscus rosa-sinensis; Malvaceae) most commonly known as the "shoe flower" is a native of Asia, specifically China, India and the Pacific islands. The plant species name "rosa-sinensis" means "Chinese rose." It is called "shoe flower" because the flowers were traditionally used to polish shoes in Jamaica and some African countries. Hibiscus has been named the "Queen of Tropical Shrubs" perhaps because it is the most outstanding ornamental shrub that is planted in the tropics as specimen plants or grown as colorful hedges along the roads and highways. Its ubiquitous presence in the tropical and subtropical Asia has been appropriately recognized when named the state flower of Hawaii and the national flower of Malaysia. There is tremendous variety in this tropical flowering plant with over 3000 varieties that have been developed by hybridization. The interest in this plant is so great that an American Hibiscus society was formed in 1950.

Hibiscus is the best-known herbaceous shrub and flower grown in all tropical and sub-tropical countries as landscape plants and attractive roadside plants, border plants or as a container plants in greenhouses. Hibiscus is propagated by cutting, layering or grafting. Plants need moist, fertile and well-drained soils and full sun to partial shade for best flowering. In Asia, the bright flowers are favored for religious worship and rituals. In south India, the leaves and flowers are used for cosmetic purposes as well as in religious worship. The flowers and leaves are ground to a paste and used for cleaning, rinsing and conditioning hair and to make hair oils. The flowers and leaves are boiled in coconut oil and applied to hair for stimulating the growth of lustrous hair, which is also reported to be effective against dandruff. Traditional use of the flowers and leaves in India include burning them in ghee to produce a black dye used to blacken eyes and eyebrows. In Hawaii, the flowers are worn on women's hair and around the neck as garlands. In India this flower is seldom used for decorating hair perhaps due to availability of more fragrant flowers of other plants for hair decoration.

Hibiscus is a small evergreen perennial tree often pruned as a robust shrub growing up to 12 feet. The plants produce flowers all around the year. There is a large variation in leaf color, flower color and flower size among varieties. The large glossy leaves are ovate in shape, alternate and vary in color from pale green to dark-green. The edges of the leaves are either simple or serrated and the stems are smooth. The flowers have five petals surrounding a central staminal column. The style passes through the center of the staminal column. The ovary consists of five carpels and numerous stamens are joined together to form the staminal column. The style ends in a five-style branch with stigmas at their tips, one for each of the five carpels in the ovary.

The flowers and buds have a mild flavor and are edible in many parts of the world especially in Hawaii. The petals are cooked with lemon and sugar, to flavor bakery, and can be used in salads, pickles, stuffed or made into fritters. The flowers are dried and processed into herbal teas. The commercial use of the leaves and flowers include use in the manufacture of hair oils and tonics and shampoos and conditioners.

In Ayurvedic medicine, the hisbiscus flower and leaf extracts are used to regulate the menstrual cycle and to treat problems related to the menstrual cycle in women (1). Hibiscus flowers are reported to possess anti-fertility property by ancient Ayurvedic texts. The roots are used to treat veneral diseases and flower extracts to prevent unwanted pregnancies at an early stage.

The flowers are good sources of b-carotene (2), flavanoids (3) and contain Calcium, Phosphorus, Iron, Thiamine, Riboflavin, Niacin, and Vitamin C (4). Researchers have reported that Hibiscus leaf and flower extracts have an anti-fertility effect on female and male rat species (5-9).

REFERENCES

1. Telefo PB et al. 1998. Effects of an aqueous extract of Aloe buettneri, Justicia insularis, Hibiscus macranthus, Dicliptera verticillata on some physiological and biochemical parameters of reproduction in immature female rats. J Ethnopharmacol 63:193-200
2. Chauhan G et al. 1996. Beta-carotene content of some native plant foods of hill region. Indian J. Ecol. 23(1): 59-61.
3. Hanny BW et al. 1972. Identification of carotenoid constituents in Hibiscus syriacus. J. Agr. Food Chem. 20: 914-16.
4. Duke JA and Ayensu ES. 1985. Medicinal Plants of China, Reference Publications Inc. 1985
5. Gupta I et al. 1985. Fertility regulation in males: effect of Hibiscus rosa-sinensis and Malva viscus flower extract on male albino rats. Proc. Natl. Acad. Sci. 55(4):262-267.
6. Zhou M et al. 1998. Study of antifertility agent in petroleum extract of Hibiscus rosasinensis L. flower. Yunnan Daxue Xuebao, Ziran Kexueban. 20:170-171, 174.
7. Tu Y et al. 1998. Studies on the antifertility constituent of Hibiscus rosa-sinensis L. (HR-1). Yunnan Daxue Xuebao, Ziran Kexueban 20:166-169.
8. Jiang Y et al. 1998. Effect of petroleum ether extract of Hibiscus rosa-sinensis flowers on early pregnancy and some reproductive hormones in rats. Yunnan Daxue Xuebao, Ziran Kexueban 20:162-165.
9. Murthy DR et al. 1997. Effect of benzene extract of Hibiscus rosa sinensis on the estrous cycle and ovarian activity in albino mice. Biological And Pharmaceutical Bulletin 20(7): 756-8.

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