Actinoscirpus grossus (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Actinoscirpus grossus (L.f.) Goetgh. & D.A. Simpson

Protologue: Kew Bull. 46: 171 (1991).

Family: Cyperaceae

Chromosome number: 2n= unknown

Synonyms

Scirpus grossus L.f. (1781), Hymenochaete grossa (L.f.) Nees (1834), Schoenoplectus grossus (L.f.) Palla (1911).

Vernacular names

• Giant bulrush (En)
• Indonesia: mensiang (western Sumatra), lingi (Javanese), walingi (Sundanese)
• Malaysia: rumput menderong, rumput menerong, rumput morong
• Philippines: tikiu, titiu (Tagalog), agas (Bikol)
• Thailand: kok, kok prue, kok saamliam (central, Bangkok)
• Vietnam: chi cói dùi.

Origin and geographic distribution

A. grossus probably originated in South-East Asia and is widely distributed in the Old World tropics from India, Sri Lanka and southern China throughout South-East Asia to the Bonin Islands (south of Japan), Micronesia and tropical Australia.

Uses

In Indonesia the stems of A. grossus are commonly utilized for the production of cheap but strong and durable products such as coarse mats and bags, and for lining pandan mats. A. grossus is usually preferred to other Cyperaceae , except Fimbristylis umbellaris (Lamk) Vahl. In Malaysia it is the most commonly used sedge, chiefly in Perak and to the north of Perak. Stems have been used locally as string or rope. In the Philippines the whole stems serve for making thick sleeping mats, whereas the split stems are employed for fine mats. The stems are also used for making bags and baskets in the Philippines. In Thailand it is used for making mats. In India it is used for plaiting mats, bags and baskets and for roofing. In Peninsular Malaysia A. grossus sometimes forms up to 90% of the herbage in rice fallows and is ploughed in as green manure. In India the tubers are eaten raw or ground into flour to make bread. The tubers are also used medicinally in India for stopping vomiting and diarrhoea and are credited with, among others, astringent, laxative, tonic, cooling and diuretic properties. A. grossus can also be used as a fodder.

Production and international trade

No production or trade statistics of A. grossus are available. Within Thailand stems are brought from the Bangkok area to Khon Kaen when local supplies are short.

Properties

Pulping experiments with A. grossus in Indonesia showed it can yield pulp of moderate quality. On average the ultimate fibre length was 1.6 mm, the diameter 5.3 μm and the lumen width 2.1 μm. The plants contained 61.8% cellulose, 26.1% lignin, 21.2% pentosans, 11.5% ash and 8.3% silica. The solubility was 6.9% in alcoholbenzene, 10.1% in cold water, 14.4% in hot water and 49.7% in a 1% NaOH solution. With a beating time increasing from 0 to 30 minutes, the freeness of unbleached and bleached (value between parentheses) pulp sheets increased from 18(17)SR to 66(56)SR, the burst factor from 32(17) to 54(26), and the folding endurance from 2300(3200) m to 4400(7600) m, whereas the tear factor decreased from 133(64) to 47(17).

A. grossus tubers are sweet and starchy and considered to be highly nutritious. They contain 60-80% digestible carbohydrates and 7-12% protein.

Description

An erect, stout, rhizomatous perennial herb, up to 2 m tall, with rather long runners 5 mm thick ending in small tubers. Stem sharply 3-angled with concave sides, 80-200 cm × 0.5-2.5 cm, smooth, spongy, strongly septate-nodulose, with a corm-like hard enlargement at base, growing singular, in small groups or in dense tufts. Leaves basal, few, sheathed, pale yellow; sheath spongy, prominently septate-nodose, tightly surrounding the stem base; blade sublinear, 50-180 cm × 1-3 cm, in the lower half keeled and 3-sided, somewhat thickish, soft, strongly septate-nodulose, in the upper half almost flat and gradually acuminate, margin subscabrous. Inflorescence terminal, corymbiform with primary, secondary and tertiary rays, 6-15 cm long; involucral bracts 3-4, leaf-like, flat, linear, 15-70 cm long, at least 2 overtopping the inflorescence; primary rays several, spreading, unequal, scaberulous, secondary rays 1-4 cm long; spikelets numerous, solitary, peduncled except terminal one, ellipsoidal, 4-10 mm × 3.5-4 mm, with many bisexual flowers; glumes spirally arranged, appressed, concave-ovate, about 3 mm × 2 mm, membranous, glabrescent, midrib prominent and green, sides red-brown with finely ciliolate margins, apex obtuse to short mucronulate; hypogynous bristles (perianth) 4-6, retrorsely scabrous, slightly longer than the fruit; stamens 3, very short, with linear anthers about 1 mm long; style 3 mm long, in upper half branching into 3 stigmas. Fruit a nut-like, trigonous, obovate achene about 1-2 mm × 1 mm, apiculate, brown.

Growth and development

In the Philippines A. grossus flowers from May to November. It spreads by runners and by fruits, the latter being dispersed by water and animals.

Other botanical information

The taxonomy of the Cyperaceae , particularly of the genus Scirpus L. s.l., is far from stabilized. For a long time, A. grossus (as Scirpus grossus L.f.) formed the section Actinoscirpus in the genus Scirpus but in addition to the name used now, it has also been classified in Hymenochaeta Beauv. ex Lestib. and Schoenoplectus (Rchb.) Palla. Hymenochaete , however, is a name used earlier for fungi ( Hymenochaete Lév.) and thus not available for Cyperaceae . A. grossus would fit in Schoenoplectus for several characteristics, but its leafy, spreading inflorescence bracts do not fit. Therefore it is preferable to keep it in a separate genus rather than widening the circumscription of Schoenoplectus . A. grossus is the only species in the genus Actinoscirpus (Ohwi) R.W. Haines & Lye. Due to its wide distribution it is quite variable and several infraspecific taxa have been distinguished. Var. kysoor (Roxb.) Noltie (synonyms: Scirpus grossus L.f. var. kysoor (Roxb.) Clarke, S. kysoor Roxb.) is restricted to India, Pakistan, Nepal, Bangladesh and Burma (Myanmar), and has hispid stem angles, glumes narrowed towards apex and strongly mucronate, and bristles plumose with twisted, spreading, glandular, multicellular hairs. Var. grossu s (distribution as the species) has smooth stem angles, glumes with wide rounded apex and minutely apiculate, and bristles not plumose but with sharp, backward pointing, unicellular hairs.

Ecology

A. grossus occurs, often abundantly, in swampy or inundated locations, pools, ditches and rice fields, from sea level up to 900 m altitude. It is an important aquatic weed in South-East Asia. In Indonesia it is considered a weed of minor importance in lowland-irrigated and tidal rice fields, where it can be controlled manually, by deep-ploughing before seed formation, or with herbicides. In Peninsular Malaysia it is one of the major weeds of transplanted rice.

Propagation and planting

A. grossus can be propagated by seed and by stolon parts.

Husbandry

In north-eastern Thailand stands of A. grossus (and Cyperus corymbosus Rottb.) are often protected by fences to prevent grazing by buffalo or cattle, implying some degree of controlled cultivation.

Diseases and pests

The dark-headed rice-borer Chilotraea polychrysa (synonyms: Chilo polychrysa , Proceras polychrysa ) feeds on A. grossus in Indonesia.

Handling after harvest

In Indonesia the stems of A. grossus are prepared by removing one of the ribs, after which they are dried, flattened (e.g. with a stump knife or piece of bamboo) and bleached in the sun and dew. In Thailand the stems are cut to the required length, split 2 or 3 times, hung to dry on special racks and often dyed a bright colour before being woven into mats on simple, hand-operated looms.

Genetic resources and breeding

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

Prospects

A. grossus will remain important as a local source of cheap but strong weaving material, providing an additional source of income for rural people, e.g. in the Philippines. It may have potential as a raw material for paper making, though this needs more research.

Literature

• Goetghebeur, P. & Simpson, D.A., 1991. Critical notes on Actinoscirpus, Bolboschoenus, Isolepis, Phylloscirpus and Amphiscirpus (Cyperaceae). Kew Bulletin 46: 169-178.
• Heyne, K., 1927. De nuttige planten van Nederlandsch-Indië [The useful plants of the Dutch East Indies]. 2nd Edition. 3 volumes. Departement van Landbouw, Nijverheid en Handel in Nederlandsch Indië. (3rd Edition, 1950. W. van Hoeve, 's-Gravenhage, the Netherlands / Bandung, Indonesia.). pp. 308-309.
• Joedodibroto, R., Widyanto, L.S. & Soerjani, M., 1983. Potential use of some aquatic weeds as paper pulp. Journal of Aquatic Plant Management 21: 29-32.
• Katigbak, S.B. & Zerrudo, J.V., 1981. Development of packages from woven indigenous materials. Forpride Digest 10: 58-62.
• Kern, J.H., 1974. Cyperaceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Series 1, Vol. 7(3). Noordhoff International Publishing, Leiden, the Netherlands. pp. 498-499.
• Kostermans, A.J.G.H., Wirjahardja, S. & Dekker, R.J., 1987. The weeds: description, ecology and control. In: Soerjani, M., Kostermans, A.J.G.H. & Tjitrosoepomo, G. (Editors): Weeds of rice in Indonesia. Balai Pustaka, Jakarta, Indonesia. pp. 260-261.

Authors

P.C.M. Jansen & M. Brink