Curculigo Gaertn. (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Curculigo Gaertn.

Protologue: Fruct. sem. pl. 1: 63 (1788).

Family: Hypoxidaceae

Chromosome number: x= 9;C. capitulata,C. latifolia: 2n= 18

Major species and synonyms

• Curculigo capitulata (Lour.) Kuntze, Rev. gen. pl. 1: 703 (1891), synonyms: C. recurvata Dryand. (1811), Molineria capitulata (Lour.) Herb. (1837), Curculigo glabra Merr. (1907).

• Curculigo latifolia Dryand., in Aiton, Hort. Kew., ed.2, 2: 253 (1811), synonyms: C. sumatrana Roxb. (1832), Molineria latifolia (Dryand.) Herb. ex Kurz (1864), Curculigo villosa Wall. ex Kurz (1869).

Vernacular names

• General: Vietnam: chi sâm cau.

• C. capitulata : palm grass (En)
• Indonesia: bedur (Javanese), congkok (Sundanese), nyeyor-nyeyoran (Madurese)
• Malaysia: lumbah merah
• Philippines: abang-abang (Bikol), atukgan (Igorot), tolábang (Ifugao)
• Thailand: tong kaai (northern).

• C. latifolia : Brunei: lemba
• Indonesia: marasi (Sundanese), keliangau (Bangka), doyo (Kalimantan)
• Malaysia: lumbah, lembah, lumbah rimba
• Thailand: chaa laan, ma phraao nok khum (northern), phraa nok (peninsular)
• Vietnam: sâm cau lá rộng.

Origin and geographic distribution

Curculigo comprises about 20 species distributed in the tropics, but most species are also cultivated worldwide as ornamentals. In Malesia 5 species are indigenous. C. capitulata occurs from South Asia (India, Sri Lanka, Bangladesh, Nepal) through South-East Asia to Taiwan, Australia and the Pacific Islands (Solomon Islands, Hawaii). In Malesia it occurs in Peninsular Malaysia, Singapore, Indonesia (Sumatra, Java, Sulawesi, the Moluccas), the Philippines (Luzon, Negros, Biliran, Mindanao), New Guinea and Manus Island. C. latifolia occurs in India, Burma (Myanmar), Thailand, Malaysia (Perak, Pahang, Sarawak, Sabah), Indonesia (Sumatra, Bangka, Lingga, Java, Kalimantan) and the Philippines (Palawan, Balabac, Samar).

Uses

In Borneo and Peninsular Malaysia the leaf fibres of C. latifolia are made into fishing nets. In Borneo, they are also used to make ropes, twines, sarongs, rice bags and garments. The cloth made from the fibre is known as "lemba" cloth. The leaves of C. latifolia are rolled into strings. In Indonesia and Malaysia they also serve to wrap fruits, vegetables and other goods for transport. The uses of the leaves of C. capitulata in Indonesia are similar to those of C. latifolia . The hill people of Camarines in Luzon (the Philippines) make false hair from the leaf fibres of C. capitulata . In Ifugao (Luzon) children use C. capitulata for warp in toy looms. The Lahu of northern Thailand use the leaves of C. capitulata like banana leaves for wrapping.

The fruits of both C. capitulata and C. latifolia are edible. The fruits of C. latifolia taste like sweetened cucumber and increase the appetite. Though the fruits are not extremely sweet themselves, they produce a very sweet aftertaste when a drink is taken after eating the fruit. This also occurs when a sour substance is taken after the fruits, so native people eat the fruits to give a sweet taste to sour foods.

In Peninsular Malaysia infusions of the leaves, stem-tips and roots of C. latifolia are all used internally against fever. Decoctions of the flowers and roots are taken as a stomachic and diuretic, whereas rhizome decoctions serve to treat menorrhagia and are applied as a lotion against ophthalmia. The rhizomes are also used against eye diseases in north-eastern India. In Borneo the leaves of C. latifolia play a role in magical healing ceremonies. C. latifolia , C. capitulata and other Curculigo spp. are also grown as ornamental plants, e.g. in Indonesia, India, Africa, Europe and the United States.

Production and international trade

C. capitulata and C. latifolia are used locally throughout South-East Asia, but no production or trade statistics are available.

Properties

The leaves of C. latifolia are tough, thin and broad, which makes them very suitable as wrappings. The fibres obtained from the leaves are relatively hard and, contrary to cotton fibres, very durable in a humid warm climate, which is probably due to their resistance to fungi. Garments made of these fibres by the Benuaq of Borneo cannot be torn and may last a lifetime. No published information is available on fibre dimensions or chemical composition.

The taste-modifying properties of the fruits of C. latifolia are due to the presence of the protein curculin. Curculin is a dimer of two identical polypeptides of 114 amino acid residues. It has a sweet taste which disappears rapidly. When taken after curculin, water tastes sweet, and sour substances likewise seem to taste sweet. For instance, a lemon eaten after taking curculin elicits a sweet taste lasting for about 10 minutes. Curculin starts to be synthesized in the fruit a week after pollination and its content increases rapidly (from 0.16 to 1.8%) between 3 and 4 weeks after pollination, shortly before the fruit ripens.

Adulterations and substitutes

In Sarawak stronger and more durable strings are made from the bast of Artocarpus elasticus Reinw. ex Blume.

Description

Perennial herbs, hairy or glabrous, with a thick rhizome. Leaves radical, often petiolate, linear to broadly elliptical. Inflorescence a raceme or spike, sometimes head-like, with few to many flowers; tepals united in a short to elongated tube; stamens 6, free, inserted at the mouth of the tube; pistil with 3-celled ovary, a short, columnar style, ending in 3 oblong stigmas. Fruit fleshy, berry-like, indehiscent or irregularly dehiscent, often with a persistent beak, with few seeds. Seed black, subglobose; testa striate; funicle usually dilated.

• C. capitulata . A hairy herb, up to 1.5 m tall. Petiole up to 1 m long; blade elliptical to broadly elliptical, 60-150 cm × 5-15 cm, nearly glabrous. Inflorescence a deflexed and head-like raceme, 2.5-7 cm × 2.5-7 cm; peduncle 7-30 cm long, tomentose to glabrescent at fruiting; bracts 1.5-5 cm long, brownish, villous to glabrescent at fruiting; flowers yellow, villous, subsessile; perianth-tube 1-2 mm long, lobes 6-8 mm long. Fruit globose to ovoid, 10-15 mm long, not beaked, whitish to green; pulp white, not very sweet.

• C. latifolia . A hairy herb, up to about 1 m tall. Petiole up to 1 m long; blade elliptical to broadly elliptical, 30-100 cm × 5-10 cm, subglabrous. Inflorescence ovoid to cylindrical, compact, 2-6 cm × 2-6 cm; peduncle 0-4(-10) cm long, glabrescent; bracts 1-6 cm long, green, glabrous or ciliate at margins; flowers subsessile, yellow, villous, subsessile; perianth tube 8-40 mm long, lobes 8-12 mm long. Fruit ovoid, 10-25 mm long, long-beaked, white to green; pulp sweet.

Growth and development

C. latifolia flowers throughout the year in South-East Asia. The fruits start to fall about 4 weeks after pollination.

Other botanical information

Curculigo has been variously included in the Amaryllidaceae and the Liliaceae , but is nowadays usually considered as belonging to the comparatively small family Hypoxidaceae . The Hypoxidaceae differ from the Amaryllidaceae by their racemose or capitate, bracteate inflorescences; they never have the umbellate inflorescences with spathes found in the Amaryllidaceae . Within the Hypoxidaceae the genera Curculigo Gaertn. and Molineria Colla are closely related. Flora Malesiana considers both names as synonyms and maintains the oldest name Curculigo , and this view is followed here. Others distinguish the 2 genera as follows: Molineria are large plants with capitate inflorescences, anthers dorsifixed with introrse opening, seed with uneven contour and without expanded hilum and strophiole; Curculigo are smaller plants with 1-few-flowered inflorescences, anthers basifixed with latrorse opening, seed smooth and glossy with an expanded hilum and strophiole. If Molineria is accepted as a separate genus, the two species described here belong to it.

Based on the length of the perianth tube, C. latifolia has been subdivided into 2 varieties:

• var. latifolia . Perianth tube 8-15 mm long; occurring in forests at high altitudes in India, Burma (Myanmar), Thailand, Malaysia (Pahang, Sarawak, Sabah), Indonesia (Sumatra, Bangka, Lingga, Java, Kalimantan) and the Philippines (Palawan, Balabac, Samar).

• var. megacarpa (Ridley) Geerinck (synonym: C. megacarpa Ridley). Perianth tube 20-40 mm long; occurring in rain forests at high altitudes in Thailand, Malaysia (Sabah, Perak) and Indonesia (Java).

C. orchioides Gaertner is a well-known medicinal plant also occurring in South-East Asia.

Ecology

Curculigo spp. are shade-loving plants, thriving under partly shaded or sunless conditions, with abundant water supply. In experiments in the open field, C. latifolia grew only very slowly and the leaves remained small. Curculigo prefers fertile, well-drained soils, rich in organic matter. In Java C. capitulata occurs in primary and secondary forest up to 2000 m altitude and C. latifolia in rain forest up to 1100 m altitude.

Propagation and planting

Curculigo can be propagated by division, suckers or freshly sown ripe seed. C. latifolia produces numerous suckers, which can be removed and easily grown into new plants. The Benuaq of Borneo dig up the rhizomes, divide them and wrap the rhizome pieces with some earth in banana leaves held together with rattan. After sprouting, the plants are planted out near the house.

In vitro clonal propagation of C. latifolia is possible, with the best results being obtained with rhizome cultures. For this, a half-strength Murashige and Skoog medium was used, supplemented with sucrose (30 g/l), thiamine (0.4 g/l), coconut water (150 ml/l), kinetin (5 mg/l) and indole-acetic acid (2.5 mg/l). Survival of the potted-up plants was about 90%.

Husbandry

Curculigo is easy to cultivate, but requires ample water supply and very good drainage. It responds well to mulching.

Harvesting

When harvested for fibres in Borneo, the leaves of C. latifolia are simply cut off at ground level. The most suitable time to harvest fruits to obtain curculin is about 4 weeks after pollination, just before the fruits start to fall.

Yield

No statistics are available on fibre and fruit yields of Curculigo .

Handling after harvest

The fibre is extracted by scraping the leaves of C. latifolia carefully with a knife. Alternatively, the petiole and leaf tip are cut off and the leaves are soaked in water for some days, then the fibres are removed by scraping with a knife or a piece of bamboo and dried for several days. The Benuaq of Borneo submerge the leaves in water, pull out the veins from the leaves and wash the veins immediately. They are bundled, tied together and hung to dry in the sun. After some time, the bundled individual veins are split manually one by one, starting from the lower end. Each vein yields a large number of fine fibres, which are combed out manually and spun into thread which can be woven. Spinning is done by twisting several individual fibres together with the fingers. The thread is not longer than the original leaf veins, as the spinning of longer threads is unknown to the Benuaq. The bundled threads are coloured with plant dyes obtained from, for example, Bixa orellana L. (orange-red) and Eusideroxylon zwageri Teijsm. & Binnend. (black). The Ikat technique may be applied. Because of the limited length of the threads, only small pieces of cloth (25-50 cm long and wide) are woven, which are sewn together into garments ("ulap doyo"). The Kenyah in Sarawak plait the freshly picked leaves of C. latifolia into strings.

Genetic resources and breeding

There are no known germplasm collections or breeding programmes of C. capitulata and C. latifolia .

Prospects

The role of Curculigo as a source of fibre will probably remain limited to local uses. C. latifolia may gain importance as a source of curculin.

Literature

• Chee Len, L.-H., 1981. Tissue culture of Curculigo latifolia Dry. ex W.T. Ait. (Hypoxidaceae). Gardens' Bulletin, Singapore 34(2): 203-208.
• Geerinck, D.J.L., 1993. Amaryllidaceae (including Hypoxidaceae). In: Kalkman, C., Kirkup, D.W., Nooteboom, H.P., Stevens, P.F. & de Wilde, W.J.J.O. (Editors): Flora Malesiana. Series 1, Vol. 11. Rijksherbarium/Hortus Botanicus, Leiden, the Netherlands. pp. 353-373.
• Lemmens, R.H.M.J. & Horsten, S.F.A.J., 1999. Curculigo orchioides Gaertner. In: de Padua, L.S., Bunyapraphatsara, N. & Lemmens, R.H.M.J. (Editors): Plant Resources of South-East Asia No 12(1). Medicinal and poisonous plants 1. Backhuys Publishers, Leiden, the Netherlands. pp. 207-210.
• Nakajo, S., Akabane, T., Nakaya, K., Nakamura, Y. & Kurihara, Y., 1992. An enzyme immunoassay and immunoblot analysis for curculin, a new type of taste-modifying protein: cross-reactivity of curculin and miraculin to both antibodies. Biochimica et Biophysica Acta 1118: 293-297.
• Yamashita, H., Theerasilp, S., Aiuchi, T., Nakaya, K., Nakamura, Y. & Kurihara, Y., 1990. Purification and complete amino acid sequence of a new type of sweet protein with taste-modifying activity, curculin. Journal of Biological Chemistry 265(26): 15770-15775.
• Zahorka, H., 1982. Traditionelle Eingeborenenkleidung für Menschen und Geister im Urwald Borneos [Traditional native clothing for people and spirits in the jungle of Borneo]. Der Palmengarten 46: 31-34.

Authors

M. Brink