Hibiscus

With colors so bold and petals so large, hibiscus are among the most flamboyant flowers in the world and easily recognized by the prominent staminal tube, typical of Malvaceae, the botanical family to which hibiscus belong. So dominant is this trait in all hibiscus, that in the species Hibiscus schizopetalus, the length of the elongated tube exceeds the diameter of the petals. Botanically, the structure is described as a merger of stamens and filaments fused together into a tube which arises from the base of the petals and surrounds the filiform style.

While all plant families have certain distinguishing features by which they are classified, kinship within each family is not always apparent. For example, Euphorbiaceae, a huge group that includes wafting garden perennials, tall trees and solitary desert cacti, can challenge the most astute botanist with its wide diversity. Malvaceae members are easier to identify. In addition to the central tube that is present in many, though not all, the flower formation of petals (usually five) is frequently arranged in an overlapping twist which is most conspicuous in the bud. Hibiscus flowers with this petal formation are referred to as "windmill type". With more than 42 genera and more than 1000 species among its members, the Malvaceae family includes many plants of economic value, such as species that yield oil, paper and fiber, and others with medicinal properties. However, the two most cultivated are Hibiscus, grown today mostly ornamentally, and Gossypium, one of the world's most important crops, and one that has profoundly influenced political and economic history.

Gossypium produces cotton. There are several varieties, including G. barbadense, G. herbaceum, G. tomentosum, G. hirsutum, and G. arboreum, which is the cotton tree native to India. If you've ever wondered exactly which part of the plant yields the fluffy white stuff that's spun into thread enough to clothe nations, it's the filaments. After the flower (yellow with purple streaks and splodge at the base) withers, the leathery seedcase is left behind, and inside this, wrapped around the black seeds, is a mass of white fibers.

Herodotus, writing in ancient Greece in the 5th century BC, reported that in India "certain wild trees bear wool instead of fruit that in beauty and quality exceeds that of the sheep; and the Indians make their clothing from these trees." Gossypium is something of a wonder plant because the seeds yield edible oil and butter substitutes, while seed residue is used for stock feed, oilcloth, putty, fertilizer, soap and nitroglycerine.

Many Malvaceae species are edible, including hibiscus. Those large, often plate-sized petals are not only luscious to look at, they're also -if not exactly luscious to eat - quite edible and quite nutritious. And though they may not be epicurean in flavor, their bright colors can enliven a salad. More flavorsome and extensively grown as a food crop is Hibiscus esculentus (syn Abelmoschus esculentus), the vegetable known as "okra".

History of hibiscus Outdoor cultivation of hibiscus Growing hibiscus in containers Propagation of hibiscus Pruning and maintenance of hibiscus Pests and diseases of hibiscus

Other Malvaceae species in garden culture include Abutilon, the Chinese lantern or flowering maple, elegant in both leaf and flower and well-adapted to mild and temperate gardens; Alcea rosea (syn Althaea rosea), the popular hollyhock; Malva parvifIora; Malvastrum coromandelinum, the false mallow; Sida fallax; Pavonia hastata, the pastel flowering shrub. But hibiscus are the showpiece of the Malvaceae, and the tropical hybrids bred from hibiscus species indigenous to many countries have produced some of the most dazzling of all cultivated flowers.

While tropical hybrids hold the limelight, species have not been banished from cultivation. Many still grow and proliferate in the wild, and others continue to be grown in gardens around the world. In all, the hibiscus genus comprises about 250 species -possibly more. Many are herbaceous and low ground plants, some grow into shrubs of shoulder height, and others into large trees. They are found mostly in climates that are tropical and sub-tropical rather than temperate. However, the hybrid progeny of these species have been bred for more cold tolerance. As a result, today's hybrids grow well outdoors in the sub-tropics and moderately well in temperate climates, while not really flourishing in the true tropics. Sub-tropical climates are distinguished from the tropics by their discernible -though slight -winter chill. Although mild, such winters are sufficient to induce a rest period, followed by spring-triggered new growth. These climates suit hibiscus well. It is here, where spring temperatures rise only a notch or two, that they take time to reach their peak, but when they do they excel, their flowers continuing long into the fall.