Economic Uses of Malvaceae - Overview

Introduction

The principle economic use of Malvaceous plants is as a source of natural fibres, the family providing perhaps the world's 3 most important fibre crops. Plants of the family are also used for food, beverages, timber, in traditional medicine, and in horticulture.

Fibre

The most important crop is cotton, which is obtained from the seed hairs of 4 species of Gossypium, the Old World diploids Gossypium arboreum and Gossypium herbaceum, and the New World tetraploids Gossypium hirsutum and Gossypium barbadense. Cotton is the world's preeminent natural fibre, of which in excess of 20 million tonnes are produced annually. This dwarfs the production of animal fibres (wool, about 1½ million tonnes annually) and is comparable to the total production of synthetic fibres. The largest producers are China, the United States of America, India and Pakistan. Production is also extensive in Central Asia, the Middle East, Australia, Brasil, and Mediterranean Europe.

Jute, obtained from the phloem fibres of Corchorus capsularis and Corchorus olitorius, is also an important fibre crop; with a production in excess of 2 million tonnes annually it is the second largest vegetable fibre. India and Bangladesh are by far the largest producers. Kenaf, obtained from the phloem fibres of Hibiscus cannabinus, has an annual production of about 1 million tonnes. Thailand, Burma, China and Bangladesh are the major producers.

Several other species are exploited for their phloem fibres, including devil's cotton, Abroma angusta, China jute, Abutilon theophrastii, roselle, Hibiscus sabdariffa and bast, Tilia sp., and many others are or were used at the subsistence level.

Kapok, the seed hairs of a number of trees belonging to Bombacoideae, particularly Bombax ceiba (250,000 tonnes annually), is not spinnable and therefore can't be used for textiles, but is waterproof. It is used primarily for insulation.

Food

The most important food crops are durian, the fruit of Durio zibethinus, which is an important plantation crop in South East Asia, okra, the fruit of Abelmoschus esculentus, which is used as a vegetable, and cacao, the fruit of Theobroma cacao, which is the source of chocolate and cacao butter. The fruits of a number of other species are also eaten. Several species, including Abelmoschus manihot and species of Corchorus and Malva, are grown as leaf vegetables. Marshmallows were originally made from the candied roots of Althaea officinalis.

Vegetable oils

Vegetable oil is produced as a byproduct (cottonseed oil, kenaf oil) of the cultivation of cottons and kenaf for fibre. A vegetable oil is also produced from the baobab (Adansonia).

Beverages

Kola nuts, the fruits of Cola nitida and other species is used commercially as a flavouring ingredient in drinks (colas or kolas). They contain stimulant alkaloids - caffeine and theobromine. Cacao is used in the production of beverages, in addition to chocolate.

Timber

Many arborescent species of Malvaceae are used for timber, some of them commercially. Perhaps the most important are Triplochiton, Mansonia and Heritiera, but Tilia, Talipariti and many other genera are used. Balsa, Ochroma pyramidale, is noted for the low density of its wood.

Medicinal

Many species of Malvoideae have been exploited for the demulcent nature of their mucilaginous sap. The best known source is marsh-mallow, Althaea officinalis.

Horticulture

Many species of Malvaceae have showy flowers, and have a place in horticulture, the number of species used in at least a small way exceeding one hundred. In temperate regions the predominant malvaceous horticultural subjects are hollyhocks, Alcea rosea, musk mallows, Malva moschata, shrub Lavateras, Lavatera ×clementii, annual Lavateras, Lavatera trimestris, hardy hibiscus, Hibiscus moscheutos and allies, and Rose of Sharon, Hibiscus syriacus.

In warmer climes to these are added tropical hibiscus, Hibiscus rosa-sinensis and Confederate Rose, Hibiscus mutabilis.

Limes or lindens, Tilia sp, are widely planted in temperate regions as shade trees in streets and parks. In tropical regions other Malvaceous species, such as the silk cotton trees, Ceiba sp, play a similar role.