Etlingera (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Etlingera elatior - 1, habit; 2, young flowering shoot; 3, inflorescence; 4, infructescence

Etlingera Giseke

Protologue: Prael. ord. nat. pl.: 209, 229, 251 (1792).

Family: Zingiberaceae

Chromosome number: x = 24, 26; 2n = 48 (E. elatior, E. hemisphaerica)

Major species and synonyms

• Etlingera elatior (Jack) R.M. Smith, Notes from the Royal Botanic Garden Edinburgh 43(2): 244 (1986), synonyms: Alpinia elatior Jack (1822), Nicolaia speciosa (Blume) Horan. (1862), Phaeomeria speciosa (Blume) Merrill (1922).

• Etlingera hemisphaerica (Blume) R.M. Smith, Notes from the Royal Botanic Garden Edinburgh 43(2): 245 (1986), synonyms: Elettaria hemisphaerica Blume (1827), Nicolaia atropurpurea (Teijsm. & Binn.) Valeton (1904), Phaeomeria atropurpurea (Teijsm. & Binn.) K. Schumann (1904).

• Other Etlingera species - see chapter on Minor spices (Etlingera rosea Burtt & Smith, E. solaris (Blume) R.M. Smith, E. walang (Blume) R.M. Smith).

Vernacular names

E. elatior

• Torch ginger (En).
• Indonesia: honje (Sundanese), kecombrang (Javanese), petikala (Moluccas)
• Malaysia: kantan (Malay), kechala (Iban, Sarawak), ubud udat (Kelabit, Sarawak).

E. hemisphaerica

• Indonesia: honje leuweung (Sundanese), honje hejo (Sundanese), honje laka (Sundanese)
• Malaysia: kantan liar (Malay).

Origin and geographic distribution

Etlingera comprises about 57 species and is distributed from India, Burma (Myanmar), Thailand, Indo-China and China throughout Malesia to Polynesia and Australia. E. elatior probably has a wide natural distribution in Malaysia and Indonesia (Java, Sumatra) but is also widely cultivated pantropically for its aromatic and decorative flowering shoots. E. hemisphaerica probably originated from Java but is now also cultivated in some other parts of Malesia.

Uses

E. elatior is the most commonly cultivated and the more valuable of the two species, but both are used very similarly. The young flowering shoots are an ingredient of curries, eaten as fresh vegetable and cooked in mixed vegetables. In Malaysia they are used for flavouring "laksa” (a special noodle dish) and many other local dishes. Less commonly, the heart of young vegetative shoots is used for flavouring dishes or eaten raw with rice. Half-ripe fruits are also applied in cooking; ripe fruits can be eaten raw, or processed into candies. E. elatior is nowadays cultivated in many tropical regions as an ornamental, even on a commercial scale as a cut flower in Hawaii and Australia. In Malaysia, a decoction of the fruit of E. elatior is traditionally used to treat earache while a decoction of the leaves may be applied for cleansing wounds. The leaves are also used by women during confinement and mixed with other aromatic herbs in water for bathing, to remove body odour. The stem is made into matting in Sumatra. The stems also have potential as raw material for the manufacture of paper. The rhizome is reported to yield a yellow dye.

Production and international trade

Etlingera is only traded fresh at local markets. Production is mainly derived from home gardens or semi-managed groves in secondary forest where Etlingera occurs naturally.

Properties

Per 100 g edible portion, flowers of E. elatior contain: water 91 g, protein 1.3 g, fat 1.0 g, carbohydrates 4.4 g, fibre 1.2 g, K 541 mg, P 30 mg, Ca 32 mg, Mg 27 mg, Fe 4 mg, Mn 6 mg, Zn 0.1 mg, Cu 0.1 mg. The composition of the heart of young vegetative shoots is very similar. The edible part of the flowering shoots consists of the receptacle and the petals, which constitute about 45% of total weight of the harvested flowering shoot. The edible heart of young vegetative shoots makes up about 20-25% of the total weight of unpeeled shoots.

Extracts of E. elatior show antimicrobial activity against various pathogenic microorganisms with minimum inhibitory concentration and minimum lethal concentration in the range of 100-800 μg/ml and 400-800 μg/ml respectively. They also display cytotoxicity against Hela (human cervical carcinoma) cells: median curative dose (CD50): 10-30 μg/ml.

The essential oil obtained by steam distillation from the young flowering shoots of E. elatior contains about 45 compounds, the main groups being aliphatic alcohols, aliphatic aldehydes and terpenoids.

Composition

Etlingera elatior: Torch ginger flowering-shoot oil (Source: Wong et al., 1993)

• 33.2% 1-dodecanol
• 17.2% dodecanal
• 13.7% α-pinene
• 7.4% dodecanoic acid
• 3.7% dodecyl acetate
• 3.3% 1-decanol
• 2.8% tetradecanol
• 2.8% 2-undecanone
• 2.8% decanal
• 1.4% 10-undecenal
• 1.2% verbenone
• 1.2% (Z)-9-tetradecen-1-ol
• 1.1% β-caryophyllene
• 0.6% limonene
• 0.5% nerolidol (unknown isomer)
• 0.4% 2-nonanol
• 0.3% decanoic acid
• 0.3% tetradecyl acetate
• 0.3% 2-tridecanone
• 0.3% β-phellandrene
• 0.3% 1-undecanol
• 0.2% 2-nonanone
• 0.2% furfuryl alcohol
• 0.2% α-terpineol
• 0.2% terpinolene
• 0.2% (Z)-5-tetradecen-1-ol
• 0.1% furfural
• 0.1% tetradecanoic acid
• 0.1% δ-3-carene
• 0.1% linalool
• 0.1% toluene
• 0.1% undecane
• 0.1% para-cymene
• 0.1% α,p-dimethylstyrene
• 0.1% α-humulene
• 0.1% myrcene
• 0.1% hexadecane
• 0.1% 9-decen-1-ol
• 0.1% decyl acetate
• trace p-cymen-8-ol
• trace 3-methylbutanol
• trace octenyl acetate (unknown isomer)
• trace β-pinene
• trace tetradecane
• trace (Z)-5-tetradecenyl acetate
• 96.9% total

Description

• Robust, perennial, tillering herbs with a rhizome at or near the ground surface or embedded deep underneath. Stems usually numerous and close together, terete with thickened base, often large and erect, up to 7 m tall, consisting of tightly telescoping leaf sheaths, with leaf blades only in the upper part.
• Leaves distichous, alternate, on short rubust petioles, large, up to more than 2 m long.
• Inflorescence headlike, lateral, arising from rhizome near base of a stem, on long slender peduncle or short erect subterranean stalk; peduncle covered with persistent, distichous scales; bracts numerous, persistent, outer involucral bracts sterile, large and coloured, inner ones smaller and gradually changing into the fertile bracts; floral bracts with one flower to each, the outer ones wider than those near the centre of the inflorescence; bracteoles embracing the flowers, tubular, deeply split, 2 or 3-toothed.
• Calyx tubular, usually with 3 short teeth, unilaterally split; corolla tubular, tube shorter or nearly as long as calyx, the 3 lobes held more or less erect; labellum short, erect or very long with lowest part erect, joined at the base to the lower part of the filament and together forming a tube, lateral staminodes absent or present as rudimentary hairy teeth or bumps; as the flower fades the labellum rolls inwards; filament very short, erect, anther large, bent forward; pistil with 3-locular ovary, style slender with broad stigma, at base surrounded by 3 shortly connate stylodes.
• Fruiting head globose or cylindrical, the fruits close together, globose or long-beaked, indehiscent, with thick pericarp. Seeds numerous, angular, surrounded by a very acid aril.

E. elatior

• Leafy stem 2.5-5 m × 2-4 cm. Rhizome thick, cream, pinkish when young.
• Leaves 15-30, the lowest much smaller than the higher ones; sheath green, sometimes tinged with red, often densely pruinose; ligule broadly orbicular, about 1.5 cm long and wide, ciliate; petiole 1-2.5(-4) cm long; blade elliptical-oblong, 20-90 cm × 10-20 cm, base rounded or cordate, margins wavy, apex with a short narrow point, glabrous but very densely and finely dotted, glossy green above, underneath often purplish when young.
• Peduncle 0.5-2.5 m × 1.5-2.5 cm; involucral bracts elliptical, 7-18 cm × 1-7 cm, crimson-pink, fleshy, spreading with apices reflexed at flowering and near the apex with a dark red appendage; floral bracts as long as or somewhat longer than the flowers, pink (but sometimes also red, purplish or white), outer ones showing a transition from the involucral bracts becoming smaller towards the centre of the inflorescence; bracteoles deeply split, about 2 cm long, white, much smaller than the flowers.
• Calyx 3-3.5 cm long, unilaterally split, 3-toothed; corolla pink, up to 4 cm long; labellum spatulate, about 4 cm long, deep crimson with white or yellow edges; stamen 2.5 cm long, filament white-hairy, anther red; style thin, red and hairy near the apex, stigma clavate, dark red.
• Fruiting head subglobose, about 10-20 cm in diameter; fruit berry-like, globose, 2-2.5 cm in diameter, with silky hairs, green when unripe, turning red at maturity.
• Seeds small, numerous, black-brown, with a white or pink, translucent aril.

E. hemisphaerica

• Leafy stem 3-7 m × 2-2.5 cm. Rhizomes robust.
• Leaves 15-25, the lowest much smaller than the higher ones, glabrous; sheath green; ligule broadly rounded, about 1.5 cm long and wide, woolly ciliate at the margin; petiole 1-2(-4) cm long; blade linear-elliptical, 15-75 cm × 5-15 cm, base rounded, sometimes subcordate or somewhat unequal-sided, margin woolly ciliate, apex shortly pointed, bronze-green, with numerous dots and reddish veins, underside wine red.
• Peduncle 35-100 cm × 1-1.5 cm, scales 5-12 cm long; inflorescence axis about 5 cm long, diameter of flowering part 7-8 cm; involucral bract broadly ovate-elliptical, 5-10 cm × 3-7 cm, red, with rounded or shortly acuminate apex with light green margin; floral bract up to 3.5 cm × 1 cm, smaller than the flower, red with pale green margin; flowers numerous, 4-7 cm long; bracteoles translucent, tinged red, up to 2.5 cm long.
• Calyx red, 3-toothed, about 3.5 cm long; corolla 4-5 cm long, tube white, lobes red with white membraneous margins; labellum broadly ovate, boat-shaped, 2-2.5 cm long, with a rounded apex and undulate margins, dark red with yellow edges except towards the base; stamen with white filament and anther crimson on back, 9 mm long; pistil with light red style and large, crimson, shining stigma.
• Fruiting head subglobose, up to 12 cm in diameter; individual fruits globose or obovoid, about 5 cm × 2.5 cm, with short hairs, beak up to 1.5 cm long, velvety yellow.
• Seeds numerous, ovoid-angular, brownish-black with white aril.

Growth and development

Etlingera starts flowering in the second year after planting a piece of rhizome. The inflorescence is adapted for pollination by birds, such as the sunbird Anthreptes malacensis.

Other botanical information

The genus Etlingera originates from 1986 when Burtt and Smith united the closely related genera Achasma Griff., Nicolaia Horan. and Geanthus Val. into one genus.

Several forms of E. elatior have been observed in the wild and in cultivation. The forms with pink involucral bracts are normally consumed as a spice. The forms with red or deep red bracts and leaves that are permanently purplish underneath, are more commonly used as ornamental or as cut flower, although the pink-bracted ones are equally popular. The white-bracted form is very rare and occurs in the wild. There are two flower types, one with a white-edged labellum (the cultivated ones) and the other with a yellow-edged labellum (the wild type).

Ecology

Etlingera grows in primary and secondary forest, in forest edges, and in secondary vegetation near villages. It occurs mainly at lower elevations and is not found in montane forest areas. Soils rich in organic matter are preferred. E. elatior is tolerant of acid soils.

Propagation and planting

Etlingera is propagated chiefly by rhizome fragments, but sometimes by seed as well. Rhizome fragments should be handled with care as the buds are rather sensitive to high temperatures and easily dry out. Since E. elatior can become very robust, it is planted at 1-2 m × 1-2 m in moist, relatively shaded locations, preferably near pools, streams or drains. Although E. hemisphaerica is seldom planted, it would need similar treatment, being equally large, robust and tillering as E. elatior.

Husbandry

Shading of Etlingera seems necessary only during the establishment phase, to protect the germinating buds. Weeding is carried out during the first 3-4 months after establishment until most weeds are shaded out. E. elatior responds well to fertilizer applications.

Diseases and pests

No serious diseases and pests are known to affect Etlingera. In cultivation trials in Sarawak some leaf-cutting insects were observed, but without significant damage to the crop.

Harvesting

Since Etlingera are perennials, flowering occurs throughout the year and continuous harvesting is possible.

Yield

No accurate yield data are available. There are some preliminary indications that the annual production of unpeeled vegetative shoots of E. elatior may easily reach 10-15 t/ha, the yield of young flowering shoots being only 0.5-1 t/ha.

Handling after harvest

Etlingera is traded fresh at local markets.

Genetic resources and breeding

There are no known germplasm collections of Etlingera. Some breeding work is being carried out to improve the ornamental value of torch ginger; some success in this respect has been reported with artificial intergeneric hybrids Etlingera × Alpinia.

Prospects

In South-East Asia E. elatior is chiefly used as a spice and to a limited extent as an ornamental. It would be interesting to investigate the potential of E. elatior for processing (pickling, canning, juice production), the production of industrial food flavours and of other natural products such as essential oils. Since knowledge of its medicinal properties is limited, research on chemical constituents and biological activity may be worthwhile. Another possible economic application is to use stems and leaves for paper production.

Literature

• Beltran, C. & Kam, Y.K., 1984. Cytotaxonomic studies in the Zingiberaceae. Notes Royal Botanic Garden Edinburgh 41(3): 541-559.
• Chen, Z.Y. & Huang, X.X., 1996. Cytotaxonomy of the tribe Alpineae. In: Wu, T.L. et al. (Editors): Proceedings of the Botany 2000-Asia Second Symposium on the family Zingiberaceae. Zhongshan University Press, China. pp. 112-121.
• Ibrahim, H., Ong, H.C. & Hassan, R., 1999. Ethnobotanical survey of the ginger-family in selected Malay villages in Peninsular Malaysia. Malaysian Journal of Science (Special edition-series B). In print.
• Kam, Y.K., 1980. The cultivation and uses of Zingiberaceae in Malaya. Federation Museums Journal 25: 191-199.
• Mertz, O., 1997. Cultivation potentials of wild vegetables: their role as cash or subsistence crops in farming systems of Sarawak, Malaysia. Ph.D Thesis. Institute of Geography, University of Copenhagen, Denmark. 200 pp.
• Smith, R.M., 1986. New combinations in Etlingera Giseke (Zingiberaceae). Notes Royal Botanic Garden Edinburgh 43(2): 243-254.
• Wong, K.C., Yap, Y.F. & Ham, L.K., 1993. The essential oil of young flower shoots of Phaeomeria speciosa Koord. Journal of Essential Oil Research 5(2): 135-138.

Sources of illustrations

Etlingera elatior: Kam, Y.K., 1980. The cultivation and uses of Zingiberaceae in Malaya. Federation Museums Journal 25. Fig. 4, p. 198 (habit, inflorescence); Ochse, J.J. & Bakhuizen van den Brink, R.C., 1980. Vegetables of the Dutch East Indies. 3rd English edition (translation of "Indische groenten", 1931). Asher & Co., Amsterdam, the Netherlands. Figs 455 & 456, pp. 757 & 758 (young flowering shoot, infructescence). Redrawn and adapted by P. Verheij-Hayes.

Authors

• H. Ibrahim & F.M. Setyowati