Malachra (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Malachra L.

Protologue: Mant. pl.: 13 (1767).

Family: Malvaceae

Chromosome number: x= 7; M. capitata: 2n= 56; M. fasciata: 2n= c. 112

Major species and synonyms

• Malachra capitata (L.) L., Syst. nat., ed. 12, 2: 458 (1767), synonyms:
  • Sida capitata L. (1753),
  • Malachra alceifolia Jacq. (1789),
  • Napaea latifolia Blanco (1845).

• Malachra fasciata Jacq., Collectanea 2: 352 (1789), synonyms:
  • Malachra lineariloba Turcz. (1858),
  • Malva horrida (Span.) Miq. (1858),
  • M. fasciata (Jacq.) Merrill (1918).

Vernacular names

• General: wild okra, malva (En).

• M. capitata : gombo bâtard (Fr)
  • Philippines: bakembakes (Ilokano), lapnis, paang-baliwis (Tagalog).

• M. fasciata :
  • Philippines: paang-baliwis (Tagalog), bakembakes (Ilokano), sutuyo (Subanon).

Origin and geographic distribution

Malachra comprises about 10 species which are native to tropical America, of which 2 or 3 have been introduced as weeds in the Old World, including South-East Asia. M. capitata is found as a weed throughout the tropics. In South-East Asia it occurs in Indonesia (West Java, Timor), the Philippines (Luzon, Panay) and Thailand. It is cultivated as a fibre plant in India, where it is known as "bhanbendi", and Central and South America. M. fasciata has also widely naturalized. In South-East Asia it is widely distributed in the Philippines and rare in West Java, Madura, Timor and New Guinea.

Uses

The bast fibre of M. capitata and M. fasciata is utilized in the Philippines for making strong rope, suitable for clotheslines and general purposes. The fibre of M. capitata is also suitable for use in coarse textiles, e.g. for sacks. It can be used as a substitute for jute (Corchorus spp.) in some applications or in admixture with jute.

In the Philippines root and leaf decoctions of M. capitata are considered emollient in enemas and for bathing purposes. Leaf decoctions of M. fasciata are used in the Philippines against gonorrhoea and rheumatism, and as a demulcent and diuretic. Leaf poultices are applied to ulcers and other sores. The roots and leaves may serve as general tonic and against haemorrhoids, fever and impotency.

In the United States Malachra spp. are considered noxious weeds.

Production and international trade

No statistics on production or trade of M. capitata and M. fasciata are available.

Properties

Fibres obtained from the stem of M. capitata are located in the secondary phloem, which is arranged in generally rectangular-shaped wedges radiating from the cambium. The fibre bundles are more or less regular, radially separated from each other by 3-4 parenchyma layers and tangentially by 1-2 layers. Each bundle contains (2-)8-20(-25) cells. The ultimate fibre cells are polygonal and prosenchymatous. They are (1.6-)2.1-2.9(-4.5) mm long, and (7-)15-16(-29) μm in diameter, with a lumen width of (2-)7(-11) μm. The dry fibre makes up about 5% of the defoliated green stem. The fibre reportedly contains 88% holocellulose, 10% lignin and 0.5% fat and wax. The quality of M. capitata fibre is good. It is long (up to 2 m or more) and generally softer, whiter and more lustrous than jute fibre. Like jute, it dries with a counter-clockwise twist. The fibre bundles are easily separated into individual strands. The elongation at break is 4.3%, which is much higher than that of jute (1-2%). The mean tenacity was found to be 0.27 N/tex, with the tenacity of fibre from the middle part of the stem (0.30 N/tex) being greater than that from the base and top sections (0.24 N/tex and 0.28 N/tex, respectively). M. capitata fibre can be spun on jute mill machinery.

The ultimate fibre cells of M. fasciata are (1.2-)2.0(-5.1) mm long and (6-)16(-42) μm in diameter, with a lumen width of (3-)7(-15) μm. The fibre of M. fasciata is white to olive-buff coloured and strong. Rope made of the bast of M. fasciata in the Philippines had a tensile strength of about 640 kg/cm²when dry and 540 kg/cm²when wet. The elongation at break of dry and wet rope was 8% and 10%, respectively.

The dipeptide derivative aurentiamide acetate has been isolated from the leaves of M. fasciata and has been shown to have antimutagenic and antimicrobial properties. Other antimutagenic compounds isolated from the leaves of M. fasciata are stigmasterol and loliolide (a monoterpene).

The 1000-seed weight of M. capitata is 3.7-4.3 g.

Description

• Annual or subperennial herbs, often partly woody, often with prickly hairs.
• Leaves alternate, simple, palmatilobed to palmatifid, stipules narrow.
• Inflorescence axillary, head-like, with bisexual flowers in axils of large, cordate, involucral bracts; peduncle usually long, pedicel extremely short; epicalyx usually absent; calyx small, cupular, often with 5 aristate segments; corolla small, petals 5, red, yellow or white; staminal column usually shorter than petals, antheriferous throughout; carpels 5, each with one ovule, style above the middle divided into 10 arms, stigmas capitate, papillose.
• Fruit a reversed pear-shaped schizocarp, mericarps triangular-subovoid, with convex dorsal side, reticulately veined, indehiscent, 1-seeded.
• Seed in form and size about similar to the mericarps.

Malachra capitata

Malachra capitata. An erect annual or perennial woody herb, up to 2 m tall, green parts with scattered, stiff, simple hairs and stiff, 2-armed, stellate hairs, prickly, about 2 mm long, for the rest densely covered with small many-armed stellate hairs. Leaves with petiole up to 9 cm long; stipules filiform, up to 1.5 cm long, hispid; blade orbicular to ovate, angular or slightly lobed, 2-9 cm in diameter, base cordate and 5-veined, margin crenate to serrate, apex obtuse to rounded, both sides densely clothed with grey, stellate hairs, glabrescent. Inflorescence a 2-10-flowered head; peduncle 1-5 cm long,; bracts 3-4, ovate to circular, 0.5-2 cm in diameter, folded along the midrib; calyx cup 3.5 mm long, segments oblong, 3 mm × 1.5 mm, obtuse, not aristate; corolla 1-1.5 cm in diameter, bright yellow, petals obovate; staminal column 3 mm long. Fruit 5-6 mm in diameter, mericarps 3 mm × 2 mm. Seed triangular-obovoid, 2.5 mm long, grey, densely stellate-hairy.

Malachra fasciata

Malachra fasciata. An erect annual woody herb, up to 2.5 m tall, green parts covered only with stiff simple hairs about 3.5 mm long, usually without minute stellate hairs. Leaves with petiole up to 12 cm long; stipules filiform, 2-3 cm long, ciliate with stiff hairs; blade circular to ovate, 3-15 cm × 2-14 cm, base rounded to shallowly cordate, 5-veined, margin coarsely serrate to crenate, apex 3-5-lobed or deeply 3-5-7-parted, both sides with scattered, appressed, simple hairs. Inflorescence a 6-9-flowered head; peduncle up to 1.5 cm long; bracts 3-4, triangular, 1-2.5 cm × 0.5-2 cm, folded along the midrib; calyx cup 4 mm long, segments ovate-acute-aristate, 2.5 mm × 1.5 mm; corolla 1-1.5 cm in diameter, white but turning red finally, petals obovate; staminal column 3 mm long. Fruit 3-4 mm in diameter, mericarps obovoid, 2.5-3 mm × 1.5-2 mm. Seed triangular-obovoid, about 2.5 mm long, black, glabrous but hilum stellate-hairy.

Growth and development

M. capitata is a slow-growing plant. In Java M. capitata and M. fasciata flower year-round. In the Philippines M. fasciata flowers from September to January.

Other botanical information

M. capitata and M. fasciata are closely allied, which is reflected in the overlap of their vernacular names in the Philippines, where both are known under the names "paang-baliwis" and "bakembakes". Sometimes M. alceifolia, here a synonym of M. capitata, is considered as a distinct species because its indumentum not only consists of minute stellate hairs as in typical M. capitata, but also of stiff, prickly, simple and stellate hairs. Differences in hairiness, which is a highly variable character depending mainly on circumstances, has led to numerous subclassifications without practical value.

Based on the degree of lobation of the leaves, 2 varieties have been distinguished in M. fasciata :

• var. fasciata: leaves 3-5-lobed, segments ovate to triangular to oblong, 1.5-2 cm wide; found in Indonesia (West Java, Timor, Irian Jaya) and the Philippines (Luzon, Panay).

• var. lineariloba (Turcz.) Gürke (synonym: M. lineariloba Turcz.): leaves deeply 3-7-parted, segments linear to long-lanceolate, 0.5-1.5 cm wide; known only from Indonesia (West Java, Madura, Timor) and the Philippines (Luzon, Mindoro, Panay, Mindanao).

Malachra is in need of a new taxonomic revision, as the last one of Gürke (1892) is badly out of date.

Ecology

In South-East Asia Malachra is generally found in waste places, fallow land, and in grassland subject to annual burning. In India M. capitata often occurs on land that tends to be inundated during rains, but it also withstands the dry conditions between monsoons. It is frequently found with Cyperus rotundus L. In South-East Asia M. fasciata occurs in waste places and on roadsides at low altitudes, presumably under seasonally dry conditions. In the Philippines it is locally abundant in wet locations and it also grows as a weed in fallow rice fields. M. capitata is a short-day plant. When sown in April-June in India flowering starts in the middle of September, with April sowings giving the highest fibre yield. M. fasciata flowers from September to January in the Philippines.

Propagation and planting

Malachra can be propagated by seed and by cuttings. Seed germination of M. capitata is often poor because of its hard seed coat, but it can be improved by seed treatment, e.g. with sulphuric acid. M. capitata must be grown at close spacings and protected from strong winds.

Husbandry

Cultivated M. capitata requires little attention.

Diseases and pests

M. capitata is a host plant of zucchini yellow mosaic virus (ZYMV), a virus causing much trouble in melon (Cucumis melo L.) and cucumber (Cucumis sativus L.).

Harvesting

In India M. capitata cultivated for fibre is harvested 3-4 months after planting.

Yield

M. capitata fibre yields of 1.9 t/ha have been obtained from experimental plantings in India. Natural stands of M. fasciata and M. capitata in the Philippines have been estimated to yield roughly about 0.2 t/ha and 1 t/ha of fibre, respectively.

Handling after harvest

In the Philippines the fibre of M. fasciata is extracted by retting: the entire plant is cut and kept in fresh water for about 10 days, after which the bast is easily stripped and freed from the nonfibrous material by washing. In the Philippines M. capitata is sometimes made into cordage without retting: the bark is simply stripped from the plant, dried and twisted into cords. In India the roots and leaves are removed from harvested M. capitata and the green stems are retted for 6-8 days in small concrete tanks. The fibre is easily separated from the retted stems because the plants do not have many lateral branches.

Genetic resources and breeding

No germplasm collections or breeding programmes of Malachra are known to exist.

Prospects

Though M. capitata is a potential source of excellent jute-like fibre and adapted to a wider range of ecological conditions than jute, the present-day use of Malachra seems very limited. It is unlikely that its importance in South-East Asia will increase beyond the current usage as cordage material. Its noxious weedy nature in the United States will deter wider use.

Literature

• Basu, N.C. & Bose, S., 1975. Effect of sowing time on the growth and yield of Malachra capitata L. Indian Journal of Agricultural Research 9(1): 43-50.
• Basu, N.C. & Chakravarty, K., 1968. Malachra capitata L., with some special reference to its growth, yield attributes and some physical aspects of its fibre. Indian Journal of Agricultural Sciences 38(3): 550-561.
• King, A.E.W., 1919. The mechanical properties of Philippine bast-fiber ropes. The Philippine Journal of Science 14(6): 561-694.
• Maiti, R.K. & Basu, N.C., 1968. Fibre anatomy of Malachra capitata L., with special reference to its ultimate fibre and fibre tenacity. Indian Journal of Agricultural Sciences 38(4): 724-729.
• Ragasa, C.Y., Peñalosa, B.A. & Rideout, J.A., 1998. A bioactive dipeptide derivative from Malachra fasciata (Malvaceae). Philippine Journal of Science 127(4): 267-276.
• van Borssum Waalkes, J., 1966. Malesian Malvaceae revised. Blumea 4(1): 1-213.

Authors

N.O. Aguilar & M. Brink