13. Medicinal plants of the Malvaceae and other families

The Malvaceae or mallow family groups those plants that have five-petalled flowers and a nutlet-like fruit. Examples include common mallow (Malva sylvestris) hairless cotton (Gossypium herbaceum), hollyhock (Althaea rosea) and marsh mallow (Althaea officinalis).

Common mallow, also known as Malva sylvestris is a herb with pink to purple flowers that are in bloom between February and March. It is distributed throughout Europe, North Africa and Asia, and grows in fields and rocky places. It was used as an expectorant and in the treatment of genito-urinary tract inflammation. It contains several vitamins an essential oil, tannins and flavonoids. The flavonoids, hypolaetin and gossypin, attribute to the analgesic, anti-inflammatory and anti-ulcer properties.

Hairless cotton (Gossypium herbaceum) has been cultivated since the Phoenician times. It flowers between July and September. Although cotton wool was produced from the hairless cotton, it was also used for its medicinal virtues. The cotton, branches and roots were used to help the uterine muscles during labour, although in pregnancy great care was taken as it is abortifacient. An important constituent in the seed oil is gossypol that has male contraceptive properties, antifungal and antibacterial properties.

Hollyhock (Alcea rosea) is one of those medicinal plants, whose origins are not known. It has pink to purple flowers, that are in bloom between April and June. It was used for throat infections, and inflammation of the intestines and skin. The expectorant and anti-inflammatory properties are attributed to phenolic compounds present in the flowers. A dye obtained from the flowers is used as a colorant in medicines and foodstuffs.

Marsh mallow (Althaea officinalis) is related to hollyhock, but it is less abundantly found. It is distributed in Europe, West Asia and North Africa. The name marsh mallow is attributed to this plant as its roots were used to flavour the soft and sweet marshmallows. It contains a high percentage of mucilage both in the flowers (20 %) and in the roots (30 %). Other constituents include scopoletine that has anti-fungal and anti-bacterial properties and phenylpropanoids that have additional anti-tumour and anti-viral properties.

Other families that contain a very small number of medicinal plants include the following.

The Cucurbitaceae or cucumber family contains a large number of edible crops such as the cucumbers, melons and pumpkins. Two important medicinal plants in this family include the squirting cucumber (Ecballium elaterium) and the pumpkin (Cucurbita maxima).

The squirting cucumber (Ecballium elaterium) is a typical Mediterranean succulent plant that flowers throughout the year except for the coldest period of the wintry months. It grows on wastelands, near the sea and on uncultivated soil. The name "squirting" is attributed to the plant due to its mode of expelling the seeds from the fruit. Its fruit juice was used in the past in the treatment of constipation, jaundice, otitis and headache. When consumed in large quantities the juice may be poisonous due to the presence of certain proteins. An important group of compounds present in this plant are the cucurbitacins. These have prominent anti-cancer properties.

Another family, called the Verbenaceae or verbena family contains three important medicinal plants; vervain (Verbena officinalis), chaste tree (Vitex agnus-castus) and the cultivated lantana (Lantana camara)

Vervain (Verbena officinalis) grows in waste places and flowers between April and December. It was commonly used for the treatment of cough, varicose veins, wounds, diabetes and to lower high body temperatures. It contains mucilage, an essential oil and a glucoside called verbenalin. This glucoside produces weak intestinal spasms that are sufficient to justify its use as a laxative.

The Chaste tree (Vitex agnus-castus) is native to the Mediterranean region and West Asia. It flowers between May and September. Traditionally, it was used to preserve chastity and to treat digestive ailments. It stimulates progesterone production.

An important and common medicinal plant of the Scrophularia or figwort family is the snapdragon (Antirrhinum majus). It is a native of West Mediterranean and grows on rocky grounds and old walls. It flowers from January till October. Traditionally it was used as an astringent, diuretic, and hearmorrhoids. It contains several constituents such as alkaloids, amino acids and glycosides.

A characteristic plant of the pokeweed or Phytolaccaceae family is pokeweed itself (Phytolacca americana). Due to its poisonous properties, it was used externally only, for the treatment of rheumatism, withlow and skin inflammation. These are probably attributed to the saponins and the oleanolic acid derivative present in the plant. It contains a pokeweed lectin stimulates the white blood cells.

A member of the Euphorbiaceae family castor bean (Ricinus communis) is renowned for its medicinal and industrial purposes. It is a native of the tropics but has naturalised in some waste places and valleys. IT flowers between March and October. Poisoning from seed ingestion has occurred in children. Traditionally, this plant was used as a laxative and to treat cradle-cap in babies. Castor oil is expressed from the seeds of the plant after they are peeled. Toxic albumins are present in the seed but these are removed by boiling with water. It is safe to use as a laxative and in baby skin products such as zinc and castor oil. It is used in industry as a lubricant to machinery and also in jet engines.

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Last Update: 11th February 2010