Hedychium (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Hedychium J. König

Protologue: Observ. bot. 3: 73 (1783).

Family: Zingiberaceae

Chromosome number: x= 17; H. coronarium: 2n= 34, 54, H. spicatum: 2n= 34

• Hedychium coronarium J. König.

• Ginger lily (En).

Hedychium comprises 40-50 species and is primarily a Himalayan genus, but occurs also throughout tropical and subtropical Asia to Malaysia, Indonesia and the Pacific Islands. Several species are cultivated throughout the tropics and subtropics as ornamentals, and some of them have become naturalized.

In Peninsular Malaysia, a decoction of the boiled leaves of different Hedychium species is eaten for indigestion. The leaves are sometimes eaten with betel nut (Areca catechu L.) to ease pain in the abdomen. The rhizome is used in local magic rites. In the Moluccas and the Philippines, a decoction of the basal part of the stem is used as a gargle for tonsilitis, and the juice of the chewed stem is applied to swellings. In Hawaii, the chewed stem is applied to infected nostrils. In Bali, the rhizome is combined with onion (Allium sativum L.) and fennel (Foeniculum vulgare Miller) in a poultice applied to the abdomen to treat fever. In Indo-China, the rhizome is considered stimulant. Rhizomes macerated in water are used to wash swollen ganglia in cattle, and some of the maceration is given to the animals to eat. In Thailand, the dried rhizome is taken as a general tonic, or more specifically for the kidneys. The rhizome is also ground and made into pills, which are given with honey to weakened patients and for muscular pains. The rhizome oil is applied as an insecticide. In India, the ground rhizome is used as a febrifuge, while in Brazil, a decoction is considered antirheumatic, tonic and excitant. In Brazil, the aromatic flowers are considered diuretic, hypertensive, antidiabetic and antisyphilitic, and are also credited with fungicidal properties.

In China, the rhizome of H. spicatum Buch.-Ham. is a remedy for stomach-ache and toothache. It is considered a fragrant stomachic and a spice. In India, the dried rhizome is reputed to be an insect repellent, and is also put between clothes for its sweet fragrance, or mixed with tobacco for smoking. The rhizomes are stomachic, carminative, stimulant and tonic, and are used for dyspepsia in the form of powder or decoction.

Thin slices of dried rhizomes of H. spicatum are sold in the markets of India, and used as a fragrance during festivals. In Indonesia, the rhizomes of H. coronarium are eaten after roasting in a fire. H. coronarium and H. gardnerianum Sheppard ex Ker Gawl. are also a source of cellulose for paper manufacture, fibres for textiles, edible starch and can be used for animal feed. In India, the rhizomes of H. coronarium are an ingredient of cosmetic powders for promoting hair growth. Fried and mixed with other ingredients, they are used as fish bait. The dried fruit is added to soften meat and pulses during cooking. The leaves are also woven into mats.

Many Hedychium species are widely cultivated as ornamentals, for their lush appearance and striking inflorescences, with often very fragrant flowers. Many cultivars and hybrids have been developed, showing variation in plant size, size and colour of the flowers and hardiness.

No statistical data are available on the production of Hedychium for medicinal purposes.

The essential oil of the fresh flowers of H. coronarium is quite different from that of the leaves and rhizomes, and contains about 300 compounds, of which the most important are linalool, (E)-isoeugenol, indole and methyl benzoate. Minor components include: α-pinene, sabinene, β-pinene, β-myrcene, 1,8-cineole, β-ocimene andα-ocimene. In Japan it was found that the methyl-benzoate level reaches a maximum at night. During the flowering period, linalool and methyl- benzoate decreased by a third, and indole decreased to trace amounts. These changes corresponded to an alteration in floral odour from a fresh, spicy, flowery, green, gardenia-jasmine-like fragrance in summer, to a monotonous odour in the winter-flowering flowers. The rhizome oil of H. coronarium from French Polynesia contains β-pinene (25%) and 1,8-cineole (40%) as major constituents, as well as the cytotoxic terpenes coronarin A-–F, (E)-λ-8(17),12-diene-15,16-dial, isocoronarin D,λ-8(17),11,13-trien-15(16)-olide and 7-β-hydroxycoronarin B. It acts as a carminative, and has a depressant effect on the smooth muscles of excised intestines of the cat. The compoundsλ-8(17),12-diene-15,16-dial and coronarin E were found in several other Malaysian Zingiberaceae.

Antimicrobial screening indicated that the essential oil from H. coronarium flowers has good activity against yeasts and fungi (plant and animal pathogens), but weak activity against the bacteria tested. In another in vitro test, essential oils of the rhizomes of H. coronarium (0.3%) and H. spicatum (1.6%) were found to be more effective against the human fungus Taenia solium than piperazine phosphate. The essential oils, however, were not as effective as hexylresorcinol against Bunostomum trigonocephalum and Oesophagostomum columbianum.

The essential oil from H. coronarium shoots inhibited mycelial growth of Aspergillus flavus at 1000 ppm and was fungitoxic at 3000 ppm.

In addition, extracts of H. coronarium are popularly used in Brazil for their supposed diuretic and/or antihypertensive properties. This has been investigated in vivo using normal- and spontaneously hypertensive rat models. Extracts were made of the leaf-sheaths in aqueous ethanol (50:50) at low temperature, after which the alcohol was evaporated. The extract showed antihypertensive and diuretic effects in the models used. Furthermore, seeds of H. coronarium show molluscicidal activity against Lymnaea cubensis and L. columella at 25 ppm. The extracts also showed some insecticidal activity against the rose aphid Macrosiphum rosae.

The rhizome of H. spicatum smells strongly of camphor, and contains an essential oil (4%) whose main compounds are the ethyl ester of p-methoxy cinnamic acid (68%), ethyl cinnamate, sabinene, 1,8-cineole, and as minor compoundsα-pinene, limonene,δ-3-carene, β-phellandrene, β-pinene, p-cymene, β-caryophyllene, β-caryophyllene oxide, linalool and elemol in varying percentages. The essential oil of the rhizome was screened against Helminthosporium oryzae and Fusarium moniliforme. Besides being fungicidal to the test fungi, the rhizome oil also proved toxic to 11 other plant pathogenic fungi. 1,8-Cineole was isolated and identified as an active constituent. Furthermore, the rhizome oil of H. spicatum showed antihistaminic activity in another test assay. In another test, the alcoholic extract of rhizomes exhibited significant anti-inflammatory activity in the carrageenan-induced hind paw oedema model in rats. It also exhibited analgesic properties in the acetic acid-induced writhing model in mice and Randall-Selitto assay in rats. Also, aqueous and ethanolic extracts of H. spicatum from China were screened in in vitro and in vivo tests, and showed marked activity.

The essential oil from the rhizomes of Indian H. gardnerianum contained pinenes (46%), other monoterpenes and about 30% sesquiterpenes, mainly cadinane derivatives. The molluscicidal action of aqueous agents of H. gardnerianum against Lymnaea truncatula collected from the Azores was studied. The extracts assayed from 1000 to 30 000 ppm, were found to be active, which might be caused by the presence of monodesmosidic saponins arising only in the water extraction. The efficacy shown by these aqueous extracts could thus lead to savings in Lymnaea truncatula control costs in the Azores. In addition, an in vitro bioassay was used to determine the antithrombin activity of dichloromethane- and methanol extracts prepared from H. gardnerianum of the Azores, and these were found to have an activity of 78% or higher in the system used.

• Erect, terrestrial or epiphytic perennial herbs, often with fleshy rhizome; stems leafy.
• Leaves distichous, penniveined, sheath long clasping; usually sessile; ligule usually prominent.
• Inflorescence a terminal spike; bracts broad and densely imbricating, concealing the rachis or narrow, enfolding the flowers; 1-6 flowers per bract, each subtended by a tubular bracteole.
• Flowers bisexual, very fragrant, white, yellow or red; calyx tubular, slender, apex unequally dentate; corolla tube slender, usually much longer than the calyx and bracts, lobes 3, long, narrow, reflexed; labellum (anterior staminode) wider than lateral staminodes, base narrow, usually conspicuously deeply bilobed, lateral staminodes 2, petaloid, as long as corolla, but wider, apex entire, fertile stamen 1, filament usually long and slender, much longer than anther, anther broadly linear, up to 10 mm long, crest absent; ovary superior, 3-locular, placentation axillary, ovules numerous, style slender, stigma pappillate.
• Fruit a globose to ovoid, 3-valved capsule, several seeds per valve. Seed with aril, deeply divided into narrow lobes.

In India, flowering of H. coronarium is from September-October, after which the growth declines and the leaves turn yellow. In Java, H. coronarium can be found flowering throughout the year.

Cladistic analysis of 29 Hedychium spp., and representatives of 16 genera belonging to 4 different related tribes in Zingiberaceae strongly supports the monophyly of Hedychium, but relationships to other genera are unclear. Within Hedychium, four major clades, which are also distinguishable on the basis of number of flowers per bract and distribution, are moderately supported.

Hedychium (except the epiphytic species) often prefers moist or temporarily flooded soils in lowland or mountainous forests or semi-shaded conditions.

Hedychium is mainly propagated by division, but propagation by seed is also possible. In vitro plant regeneration of several Hedychium species through rhizome-meristem culture has been successful.

Hedychium requires fertile, moist soils for an abundant growth. Although Hedychium is usually considered frost sensitive, a number of species grown in the temperate zone have survived temperatures as low as -7°C.

Hedychium can be attacked by leaf-spot fungi, but this rarely causes substantial damage. Several Hedychium species, including H. coronarium in South America and H. gardnerianum in Reunion, Hawaii and New Zealand, have invaded the local vegetation, where the different stages of succession become dominated by aggressively expanding populations, and it appears very unlikely that native species will replace invaders as the succession proceeds. The survival of many indigenous plant species probably hinges on the active control of Hedychium and other alien species.

A possibility for biological control of Hedychium is bacterial wilt caused by the ginger strain of Ralstonia solanacearum (synonym Pseudomonas solanacearum), which systemically infects the species. The suitability of R. solanacearum as a biological control agent in Hawaii was investigated by inoculating seedlings and rooted cuttings of native forest plants, ornamental gingers, and solanaceous species to confirm host specificity. No native forest or solanaceous species developed wilt or other symptoms during the study, but the bacterium caused limited infection with reversible effects near the inoculation site on H. coronarium, several other Zingiberaceae and also Musa sapientum L. All inoculated H. gardnerianum plants developed irreversible lethal symptoms. The destructiveness of the ginger strain of R. solanacearum to edible ginger has raised questions regarding its use for biological control. However, because locations of H. gardnerianum infestations are often remote, the risk of contaminating planted Zingiberaceae is unlikely.

Several herbicide treatments were evaluated for their use against H. coronarium in South America. The best treatment was picloram + 2,4-D amine sprayed on plants 22 and 60 days after sprouting, resulting in 92% and 99% control, respectively. Hand weeding killed only 36% of the weed but is a cheap form of control.

All plant parts of Hedychium used, e.g. leaves, flowers or rhizomes, are harvested when needed.

Most plant parts of Hedychium are used fresh.

Several wild Hedychium from the eastern Himalayan region of India are rare or endangered and require in situ or ex situ conservation measures. H. longicornutum is not very common in its distribution area, but collection seems limited. H. coronarium is widely cultivated as an ornamental and certainly not endangered, although its genetic diversity might be limited as the plants are often propagated vegetatively. No substantial germplasm collections of H. coronarium and H. longicornutum are known to exist. No breeding programmes are known for medicinally used Hedychium.

In South-East Asia, H. coronarium is better known as an ornamental than for its medicinal use. Its antimicrobial effects are interesting though, and merit further research. Cultivation of H. coronarium for the perfume industry could be an alternative, as the fragrant flowers yield a pleasant and delicate essence. Although H. longicornutum is locally medicinally used, knowledge on its biological activities or chemical constituents is scarce, and more research in these fields is needed.

• Anderson, R.C. & Gardner, D.E., 1999. An evaluation of the wilt-causing bacterium Ralstonia solanacearum as a potential biological control agent for the alien kahili ginger (Hedychium gardnerianum) in Hawaiian forests. Biological Control: Theory and Applications in Pest Management 15(2): 89-96.
• De Ribeiro, A., De Melo, M.M., De Barros, F., Gomes, C. & Trolin, G., 1986. Acute antihypertensive effect in conscious rats produced by some medicinal plants used in the state of Sao Paulo. Journal of Ethnopharmacology 15(3): 261-269.
• De Ribeiro, A., De Barros, F., De Melo, M.M., Muniz, C., Chieia, S., Wanderley, M.-G., Gomes, C. & Trolin, G., 1988. Acute diuretic effects in conscious rats produced by some medicinal plants used in the state of Sao Paulo, Brasil. Journal of Ethnopharmacology 24(1): 19-29.
• Kosuge, T., Yokota, M., Sugiyama, K., Yamamoto, T., Ni, M.Y. & Yan, S.C., 1985. Studies on antitumour activities and antitumour principles of Chinese herbs. I. Antitumour activities of Chinese herbs. Yakugaku Zasshi 105(8): 791-795. (in Japanese)
• Perry, L.M., 1980. Medicinal plants of East and Southeast Asia. Attributed properties and uses. MIT Press, Cambridge, Massachusetts, United States & London, United Kingdom. p. 441.
• Wood, T.H., Whitten, W.M. & Williams, N.H., 2000. Phylogeny of Hedychium and related genera (Zingiberaceae) based on ITS sequence data. Edinburgh Journal of Botany 57(2): 261-270.

• Halijah Ibrahim