Schoenoplectus (Rchb.) (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Schoenoplectus (Rchb.) Palla

Protologue: Bot. Jahrb. Syst. 10: 298 (1888).

Family: Cyperaceae

Chromosome number: x= unknown;S. lacustris:2n= 38, 40, 42;S. litoralis:n= 39, 42;S. mucronatus:n= 21, 22; 2n= 42, 44

Major species and synonyms

• Schoenoplectus lacustris (L.) Palla, Verh. K.K. Zool.-Bot. Ges. Wien 38 (Sitzungsber.): 49 (1888), synonyms: Scirpus lacustris L. (1753), S. validus Vahl (1806), Schoenoplectus tabernaemontani (Gmel.) Palla (1888), S. validus (Vahl) T. Koyama (1978).

• Schoenoplectus litoralis (Schrad.) Palla, Verh. K.K. Zool.-Bot. Ges. Wien 38 (Sitzungsber.): 49 (1888), synonyms: Scirpus litoralis Schrad. (1806), S. subulatus Vahl (1806), Schoenoplectus subulatus (Vahl) Lye (1971). Note: the epithet " litoralis " is sometimes written " littoralis ".

• Schoenoplectus mucronatus (L.) Palla, Verh. K.K. Zool.-Bot. Ges. Wien 38 (Sitzungsber.): 49 (1888), synonyms: Scirpus mucronatus L. (1753), S. triangulatus Roxb. (1820), S. sundanus Miq. (1856).

Vernacular names

• General: bulrush, sedge (En)
• Vietnam: chi cói dùi.

• S. lacustris: great bulrush, clubrush (En). Jonquine, jonc de chaisiers, scirpe des lacs (Fr)
• Philippines: tiker (Ilokano).

• S. litoralis : Indonesia: endong, penjalinan (Javanese).

• S. mucronatus : bog bulrush (En)
• Indonesia: rumput kerecut (western Sumatra), mendongan (Javanese), jajaruman (Sundanese)
• Malaysia: rumput kerechut, rumput kumbar
• Philippines: bibiran (Tagalog), parapipit (Ilokano), pulutapit (Bontoc)
• Thailand: kok klom (central), kra chuut (peninsular), yaa salaep (northern)
• Vietnam: cói dùi.

Origin and geographic distribution

Schoenoplectus is a large genus with worldwide distribution, comprising more than 60 species, of which about 10 occur in South-East Asia. S. lacustris occurs worldwide in temperate and tropical areas, in South-East Asia particularly in areas bordering the Pacific. S. litoralis is distributed from the Mediterranean region and Africa through southern Asia to Australia. In South-East Asia it is rare, but it occurs in Indonesia (Java, Madura, Kangean, Lesser Sunda Islands), the Philippines (Luzon) and north-eastern New Guinea. S. mucronatus originates from Asia and is distributed in the warmer parts of the Old World, from southern Europe through South and South-East Asia to Japan and Australia; it is rare in tropical Africa. It is naturalized in North America. It is found through much of South-East Asia, but has not yet been recorded from the Moluccas. It is cultivated in western Sumatra (Padang uplands) as a source of weaving material.

Uses

The stems of S. lacustris serve for mat-making in the Philippines and India; elsewhere they are or have been used for basketwork, chair seating, thatching, paper production and as a source of cellulose. Stems of S. litoralis are used for making mats in West Java. In Ghana they serve for stuffing mattresses, and in Oman for thatching. The stems of S. mucronatus are utilized in South-East Asia for the production of sitting-mats, sacks and bags. In Papua New Guinea (Tari) the stems are made into skirts. In the past the stems of S. mucronatus were commonly used as string or rope, e.g. in Indonesia and Malaysia, but they have been replaced by synthetic products.

In India the rhizomes of S. lacustris are eaten raw or ground into flour to make bread. Medicinally, the stems are credited with astringent and diuretic properties. S. lacustris is also used as fodder and as an ornamental. It is planted to filter and clean polluted or eutrophic water. In Europe (the Netherlands, Germany) S. lacustris is sometimes planted for land reclamation along seashores. The stems of S. litoralis are used as fodder in Oman when other sources are scarce. Its rhizomes are eaten cooked as a vegetable and stems are roasted, peeled and the sections consumed, or the outer skin is removed and the pith (white interior) eaten raw or boiled.

Production and international trade

No production or trade figures of Schoenoplectus are available. In some South-East Asian areas, Schoenoplectus is traditionally important for the local economy.

Properties

Mats made of S. lacustris stems are not considered very durable. S. lacustris belongs, along with Phragmites australis (Cav.) Trin. ex Steudel and Typha latifolia L., to the main species planted for biological purification of polluted water and removal of nutrients from eutrophic water. In beds planted with these species, organic materials and inorganic nutrients are absorbed, colloidal substances precipitate, and bacteria and other pathogens are significantly reduced. Mechanisms involved are sedimentation, mechanical filtration, nutrient uptake by these plants, and the creation of attachment sites on the plants for aerobic and anaerobic microorganisms purifying the water. Under laboratory conditions S. lacustris has been shown to efficiently absorb chromium from tannery effluents and sludge.

Description

Annuals or rhizomatous perennial herbs. Stems terete or trigonal, solid, rarely transversely septate. Leaves reduced to bladeless sheaths surrounding the stem bases, rarely with short blades. Inflorescence pseudolateral and compact umbel-like, or anthelate with terminal spikelet or cluster overtopped by lateral ones, or with single spikelets; involucral bract solitary, foliar, often also stem-like and continuous with the stem, sheathing; spikelets solitary or clustered, usually many-flowered; rachilla not winged; glumes spirally arranged, keeled, mucronate, lower ones empty, upper ones not developing; flowers bisexual; hypogynous bristles or scales absent or when present persistent; stamens 1 or 3; pistil with style continuous with ovary, at apex splitting into 2 or 3 stigmatic branches. Fruit a nut-like achene, biconvex or trigonous, smooth, undulate or ridged.

• S. lacustris . A perennial herb with stout, horizontally creeping rhizome up to 1.5 cm thick. Stem stout, erect, growing in a row along the rhizome, subterete, 0.5-2 m × 0.5-2 cm, soft and easily compressed, glaucous-green. Sheaths 3-5, lower ones soon disintegrated into reticulate fibres, upper ones 10-30 cm long, rarely with up to 10 cm long blade. Inflorescence pseudolateral, compound, 5-15 cm long, consisting of many spikelets; involucral bract erect, 2-5 cm long, shorter than inflorescence; primary rays stiff, up to 5 cm long, secondary rays up to 2 cm long; spikelet solitary or in clusters of 2-3, ovoid, 5-10 mm × 4-5 mm, many-flowered, dark brown; glumes scarious, ovate with prominent midrib, 3-4 mm × 2-2.5 mm; hypogynous bristles 5-6, slightly longer than the fruit, retrorsely scabrous; stamens 3 with 2 mm long linear anthers; style at top branching into 2 stigmas. Fruit plano-convex with low rounded back, obovoid, 2 mm × 1.5 mm, grey-black.

• S. litoralis . A loosely tufted perennial herb with rhizome, runners ending in a tuber. Stem stout, terete, only obtusely trigonal just below inflorescence, 0.5-1.5 m × 3-10 mm, smooth, grey-green, clothed at base with bladeless sheaths. Sheath cylindrical, 4-20 cm long, septate-nodulose, grey-brown; blade setaceous, 5-10 mm long, recurved. Inflorescence a pseudolateral, simple umbel-like corymb, 2-8 cm long, with 3-7 unequal ascending rays up to 5 cm long, terminated by 1-3 spikelets; bract as long as inflorescence; bracteoles scale-like; spikelet solitary, ellipsoid-ovoid, 7-15 mm × 3-4 mm, many-flowered, red-brown; glumes membranous, slightly boat-shaped with slender keel, 3-4 mm × 2 mm; hypogynous scales 3-4, ligulate-spatulate, plumosely fimbriate with multicellular, backward directed hairs on upper part, slightly longer than fruit; stamens 3 with linear anthers 2 mm long; pistil with style slightly longer than achene, branching into 2 stigmas. Fruit broadly obovoid, biconvex, 2 mm × 1.3-1.7 mm, shiny brown-black.

• S. mucronatus . A tufted perennial with short rhizome. Stem erect, sharply trigonal, 25-120 cm × 2-9 mm, sides concave, dark green, striate when dry, at base tightly clothed with 1-3 sheaths. Sheath membraneous, the lowest often scale-like, upper one 3-angled cylindrical, 7-20 cm long, brown. Inflorescence pseudolateral, hemispherical, head-like, up to 4 cm in diameter, with 1-10(-25) spikelets; bract similar to stem, 1-10 cm long, narrowed at apex to a blunt pointed tip, at first erect and a continuation of the stem, finally often bent down; spikelet sessile, ovoid-ellipsoid, 6-20 mm × 3-6 mm, pale brown, many-flowered; glumes boat-shaped, ovate-circular, 3-4 mm × 2-3 mm, many-veined and with pale green prominent midrib, margin minutely ciliolate; hypogynous bristles 5-6, hard, unequal, longer than the fruit, bearing backwardly directed short fine spines, red-brown; stamens 3 with 1-2 mm long anthers; pistil with straight slender style 2.5 mm long, branching into 2-3 stigmas. Fruit compressed ob-3-pyramidal but dorsal angle indistinct, about 2 mm long and wide, sides flat to slightly convex, glossy black-brown.

Growth and development

The fruits of S. lacustris can float only for a short period (mostly less than 1 hour) and dispersal over large distances probably depends on transport by seed-consuming birds.

In Java S. litoralis and S. mucronatus flower year-round.

Other botanical information

The taxonomy of Cyperaceae is difficult, often confusing and has not yet been clarified. In the past Schoenoplectus was a section of the very large (200-300 species) and heterogeneous genus Scirpus L. At present attempts are being made to split Scirpus s.l. into smaller, more homogeneous genera and Schoenoplectus is one of those, although authors differ in opinion about its delimitation (60-80 species). In South-East Asia it comprises about 10 species, but authors also disagree here on delimitations of many species.

S. lacustris comprises 3 subspecies: subsp. lacustris , distributed in temperate and tropical Europe and Asia (including South-East Asia), Africa, Australia, Polynesia, North and Central America in fresh water only; subsp. tabernaemontani (Gmel.) A. & D. Live, distributed in temperate Europe and Asia (cultivated as a fibre crop in Korea and widely as a pond border ornamental) in brackish and in fresh water; and subsp.validus(Vahl) T. Koyama (synonym:Scirpus validusVahl), distributed in countries bordering the Pacific Ocean, growing on wet or flooded soils, particularly useful for its edible rhizomes and its culms that are used for matting and thatching in the Philippines.

S. litoralis is similar in appearance to S. lacustris , but usually has a less compound inflorescence and can be easily recognized by the flat, plumose, hypogynous scales. Plants from the Mediterranean, Middle East, China and Mongolia have stems which are triangular throughout and are sometimes classified in subsp. litoralis ; according to this classification the South-East Asian plants (as described here) belong to subsp. subulatus (Vahl) T. Koyama (synonym: var. subulatus (Vahl) Chiov.).

Some other Schoenoplectus species, occurring in South-East Asia but without recorded use as a fibre plant there, might be potential fibre sources as well: S. articulatus (L.) Palla (Mediterranean, Africa, throughout South and South-East Asia to South-East China and northern Australia) serves for thatching in India, where it is also used medicinally as a purgative. S. juncoides (Roxb.) Palla (Madagascar, from India to northern Australia) is used in South-East Asia as a forage with a high feeding value and in China it is applied medicinally to release heat, to clear the eyes and to stop coughing. It is also a weed in agricultural fields. S. lateriflorus (J.F. Gmel.) Lye (from India to Australia) is a weed in fallow rice fields in south-East Asia, where it is grazed by cattle and it serves as a green manure; in Taiwan its stem fibres are used to make hats. S. wallichii (Nees) T. Koyama (from India throughout South-East Asia to China and Japan) is used medicinally in China to alleviate cystitis.

Ecology

Most Schoenoplectus species prefer open, wet locations, such as swamps, pools, ditches, rice fields, lake shores and the banks of streams. S. lacustris is found in open marshes, open sandy foreshores and freshwater swamps, at altitudes up to 1900 m. S. litoralis occurs, sometimes abundantly, in brackish swampy locations and saline pools near the sea. It is also found at higher altitudes, e.g. at Tarogong (Java, 800 m altitude) in water originating from hot springs, and along Batur Lake (Bali, 1000 m altitude). S. mucronatus is found at altitudes of up to about 2100 m in open, wet localities, swamps, ditches, pools, lake margins and sometimes in inundated rice fields. It is often dominant or co-dominant with Leersia hexandra Swartz. In Sumatra (Padang uplands) S. mucronatus is planted in swampy rice fields and other continuously moist terrains. In Java S. mucronatus is considered a weed of minor importance in rice fields, where it can be controlled by hand, by deep-ploughing before seed formation, or with herbicides.

Propagation and planting

Most Schoenoplectus species can be propagated by seed and by division of clumps. The germination of 1-year-old S. lacustris seeds is improved by stratification (storage in demineralized water at 4°C) or bleach scarification (pre-soaking of the seeds in sodium hypochlorite). In western Sumatra planting material of S. mucronatus is obtained by division of old clumps into pieces containing 10-15 stems, which are planted out at a distance of 1 m × 1 m. Before planting, the soil is ploughed or hoed until it is mud.

Harvesting

In western Sumatra S. mucronatus stems are harvested 3-4 months after planting, when the flowers have turned brown.

Handling after harvest

In western Sumatra harvested stems of S. mucronatus are sorted, dried (1-2 days in full sun and then several days indoors) and flattened with a piece of bamboo until they become lustrous.

Genetic resources and breeding

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

Prospects

Schoenoplectus will remain important as a local source of weaving material, providing an additional source of income for rural people. It also has prospects as an ornamental for pond banks. On a global scale S. lacustris certainly has potential as a component of effective plant filter systems for the biological purification of water.

Literature

• Goetghebeur, P. & Simpson, D.A., 1991. Critical notes on Actinoscirpus, Bolboschoenus, Isolepis, Phylloscirpus and Amphiscirpus (Cyperaceae). Kew Bulletin 46: 169-178.
• Gray, K.R. & Biddlestone, A.J., 1995. Engineered reed-bed systems for wastewater treatment. Trends in Biotechnology 13(7): 248-251.
• 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.
• 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. 592-661.
• 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. 24-565.
• Koyama, T., 1985. Cyperaceae. In: Dassanayake, M.D. & Fosberg, F.R. (Editors): A revised handbook to the flora of Ceylon. Vol. 5. Amerind Publishing Co., New Delhi, India. pp. 153-164.
• Simpson, D.A. & Inglis, C.A., 2001. Cyperaceae of economic, ethnobotanical and horticultural importance: a checklist. Kew Bulletin 56(2): 257-360.
• Soto, F., García, M., de Luís, E. & Bécares, E., 1999. Role of Scirpus lacustris in bacterial and nutrient removal from wastewater. Water Science and Technology 40: 241-247.

Authors

P.C.M. Jansen & M. Brink