Boesenbergia rotunda (PROSEA)
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Introduction |
Boesenbergia rotunda (L.) Mansfeld
- Protologue: Vorl. Verzeichnis (die Kulturpflanze, Beiheft 2): 579 (1959).
- Family: Zingiberaceae
- Chromosome number: 2n = 36
Synonyms
- Curcuma rotunda L. (1753),
- Kaempferia pandurata Roxb. (1810),
- Gastrochilus pandurata (Roxb.) Ridley (1899),
- Boesenbergia pandurata (Roxb.) Schlechter (1913).
Vernacular names
- Chinese keys (En).
- Petits doigts (Fr)
- Indonesia: temu kunci (Indonesian), tumbu konci (Moluccas)
- Malaysia: temu kunci
- Cambodia: khchiëy. Laos: kas'a:y, nè:ngx kiengz
- Thailand: krachai (general), ka-aen (northern), wan-phraathit (Bangkok)
- Vietnam: bồng nga truật, củ ngải.
Origin and geographic distribution
B. rotunda is native to Java and Sumatra; it grows wild in the teak forests of Central and East Java. It is widely cultivated in India, Sri Lanka, South-East Asia (particularly in Indonesia, Malaysia and Thailand) and southern China.
Uses
B. rotunda is principally used as a spice and a medicine. In Indonesia, Malaysia, Indo-China and India it is cultivated for its rhizomes and roots, which are consumed as an aromatic spicy flavouring for food and pickles. The rhizomes and roots are commonly used in cooking throughout Java and most of Indonesia. In some parts of Malaysia, young rhizomes and roots are eaten raw, with rice; young shoots are eaten this way in Java. The young spicy shoots are also a substitute for the rhizomes. In the Caruban district (East Java), leaves are used together with those of teak as a wrapper for fermented soya bean cake ("tempeh”).
The rhizomes and roots have a wide range of applications in traditional medicine, e.g. as ingredient in post-partum tonic mixtures, as stomachic and carminative, as a remedy for coughs, indigestion, sprue and colic, and as external treatment for ringworm, rheumatic and post-partum muscular pain, swollen abdomen and difficult urination in children.
Production and international trade
B. rotunda is commonly and widely produced, traded and consumed locally in India and South-East Asia, but no statistics are available.
Properties
Per 100 g edible portion air-dried rhizomes contain approximately: water 12 g, total protein 20 g, total nitrogen 3.2 g, total sugar 12 g, soluble matter in 80% ethanol 52 g, soluble matter in water 21 g, total ash 6 g.
The constituents of the rhizomes and roots of Chinese keys include monoterpenoids (geranial and neral), flavones and flavanones (pinostrobin, alpinetin and pinocembrin) and chalcone (cardamonin). Three unusual dihydrochalcone derivatives (e.g. boesenbergin A) and three compounds related to panduratin A have also been isolated. Cardamonin (2',4'-dihydroxy-6'-methoxychalcone) is reported to be an effective anti-tumour agent.
The harvest index (fresh rhizome : total fresh plant) ranges from 0.56 to 0.64. The essential-oil content of the rhizome and roots ranges from 1-3% of dry weight, 0.2-0.5% of fresh weight. The essential oil contains the following main compounds: 1,8-cineole (18-41%), camphor (13%), d-borneol (9.2%), d-pinene (4.1%), zingiberene (2.7%), curcumin (0.9%) and zedoarine (0.7%). The essential oil from the rhizomes of Chinese keys (containing methyl cinnamate and zingiberone) has the ability to solubilize calcium kidney stones in vitro.
Description
- Perennial herb, 30-80 cm tall, with leafy shoots bearing 3-5(-7) erect leaves and about 3 bladeless, reddish sheaths at the base. Rhizome at the base of the leafy shoots only, composed of more or less globose joints, largely fused, up to 2 cm in diameter, yellow-brown outside, bright yellow inside, fragrant when bruised. Roots tuberous and fleshy, subclavate (like "Chinese keys”), 5-30 cm × 0.5-2 cm, colour and fragrance like the rhizome.
- Leaves alternate, biseriate, erect, hardly fragrant when bruised; sheaths not very robust, 9-19 cm long, together forming a short pseudostem; ligule broadly triangular, up to 1.5 cm long, arachnoid-pubescent, auricled, soon withering; petiole canaliculate, up to 30 cm long, glabrous; blade elliptical-oblong to broadly lanceolate, 12-50 cm × 5-17 cm, dark green, glabrous, with several raised, parallel veins and scattered dots above, pale green, glabrous to arachnoid-pubescent and densely white-dotted below.
- Inflorescence terminal on leafy shoot, spike-like, 10-15 cm long, almost completely hidden by the upper leaf sheaths, bearing about 10 flowers; peduncle 1-2 cm long; rachis short, crowded with distichous, equitant bracts; flowers far exserted, appearing in succession, situated in the axil of a bract and a bracteole; bracts and bracteoles oblong-lanceolate, 4 cm × 0.7 cm, green.
- Calyx shortly tubular, about 1.5 cm long, apex bifid; corolla with an about 6 cm long white tube and 3 unequal, oblong, up to 1.7 cm long, incurved, pink lobes at apex; labellum (central staminode) patent, oblong-obovate or panduriform, 2-3.5 cm × 1.5-2.5 cm, apex crenate, undulate plicate, upper half pink, lower half white or pale pink, with red-violet dots within; lateral staminodes erect, petaloid, broadly obovate, 1.5-2 cm × 1 cm, pink; stamen with 5 mm long white hairy filament and 5 mm long yellow-white anther with narrow, bilobed, reflexed apical appendage of connective (crest), anther dehiscing longitudinally; pistil with 3-loculed, glabrous ovary 5.5 mm long, stylodes slender, style filiform, stigma protruding beyond the anther, funnel-shaped, yellow-white.
- Fruit unknown.
Growth and development
A rhizome cutting planted in the open produces 4-5 leaves in about 1 month after planting; under shade, only 2 leaves are produced. The growth rate is fast for plants cultivated in well-drained loams, rich in organic matter. During its growth, the mother tuber emits, long, straight, swollen carrot-like roots resembling Chinese keys. Plants grown in shady locations lose their cineole content much faster than those grown in sunny places. When grown for the rhizome and roots as a spice, the life cycle of a plant is about 5 months. Plants can produce young shoots for vegetable use and rhizome and roots for medicinal use for several years. If left undisturbed a plant may develop into a gregarious community. In India plants flower in August, in Cambodia in June.
Other botanical information
The genus Boesenbergia Kuntze comprises about 40 species, distributed throughout India and the western part of South-East Asia. The taxonomy of the genus is poorly known.
Ecology
Chinese keys is found in mixed deciduous and evergreen forests, on limestone hills along streams, from sea-level up to 1200 m altitude. It grows best in a hot, humid tropical climate, on relatively fertile soils with good aeration and drainage.
Propagation and planting
Propagation of B. rotunda is by cuttings from the old rhizome, situated immediately under the leafy shoot. The cuttings are planted at the beginning of the rainy season, preferably on hillocks, at distances of 30-40 cm × 30-60 cm.
Husbandry
Provided water supply is sufficient, not much care is needed. Weeding is necessary until the plants are well established. It is recommended to apply NPK fertilizer 2 weeks and 4 weeks after planting, with a total dosage per ha of 100 kg N, 25 kg P and 50 kg K.
Diseases and pests
No serious diseases and pests are known of B. rotunda. Occasionally larvae of Kerana sp. and Udaspes sp. feed on the leaves.
Harvesting
Young shoots to be used as a vegetable can be cut from 1-2 months after planting. Whole plants are pulled up at 4-5 months after planting for use as cooking spice and traditional medicine. If not harvested within 5 months after planting, rhizomes will become woody and their quality as a spice will decrease. Specific parts of the plant, e.g. the enlarged roots for external use as medicine, can be selectively harvested later than 6 months after planting, without disturbing the growth of the plant.
Yield
The average yield of fresh rhizomes and roots is about 10-30 t/ha at 4-6 months after planting. Being mainly a crop of smallholders for domestic use only, yield data are scarce.
Handling after harvest
After harvesting, the parts are cleaned and washed before marketing. The mother rhizomes are kept apart for propagation.
Genetic resources and breeding
No germplasm collections or breeding programmes are known to exist for Chinese keys.
Prospects
Chinese keys is quite widely used as cooking spice and as folk medicine in South-East Asia but its chemical composition is still insufficiently known. Further research on the chemical constituents and biological activity is urgently needed to exploit its full potential, and germplasm collection is recommended.
Literature
- 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.
- Nugroho, A., 1997. Pengaruh macam media terhadap pertumbuhan dan kualitas hasil tanaman temu kunci (Boesenbergia pandurata (Roxb.) Schlecht.) [Effect of several media on the growth and yield quality of Chinese keys (Boesenbergia pandurata (Roxb.) Schlecht.)]. Faculty of Agriculture, Brawijaya University, Malang, Indonesia.
- Nugroho, A. & Hidayat, F., 1997. Survei habitat tumbuh dan penyebaran tanaman temu kunci (Boesenbergia pandurata (Roxb.) Schlecht.) di beberapa daerah Jateng dan Jatim selama musim hujan [Survey of habitat and distribution of Chinese keys (Boesenbergia pandurata (Roxb.) Schlecht.) in some parts of Central and East Java during the rainy season]. Faculty of Agriculture, Brawijaya University, Malang, Indonesia.
- Pandji, C., Grimm, C., Wray, V., Witte, L. & Proksch, P., 1993. Insecticidal constituents from four species of the Zingiberaceae. Phytochemistry 34(2): 415-419.
- Sasmito, E., 1995. The effect of essential oil of temu kunci (Boesenbergia pandurata Roxb.) on calcium kidney stone solubility in vitro. In: Kit, C.L. et al. (Editors): Proceedings on "Trends in traditional medicine research”. The School of Pharmaceutical Sciences, Universiti Sains Malaysia, Pinang: 452-457.
- Sirirugsa, P., 1992. A revision of the genus Boesenbergia Kuntze (Zingiberaceae) in Thailand. Natural History Bulletin Siam Society 40: 67-90.
Sources of illustrations
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. Fig. 452, p. 751 (habit, tuberous roots); Sirirugsa, P., 1992. A revision of the genus Boesenbergia Kuntze (Zingiberaceae) in Thailand. Natural History Bulletin of the Siam Society 40: 67--90. Fig. 6, p. 78 (inflorescence, flower). Redrawn and adapted by P. Verheij-Hayes.
Authors
- H. Ibrahim & A. Nugroho
