Scirpodendron ghaeri (PROSEA)
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Introduction |
Scirpodendron ghaeri (Gaertn.) Merr.
- Protologue: Philipp. J. Sci., Bot. 9: 268 (1914).
- Family: Cyperaceae
- Chromosome number: 2n= unknown
Synonyms
Chionanthus ghaeri Gaertn. (1788), Pandanus caricosus Spreng. (1826), Scirpodendron costatum (Thw.) Kurz (1869).
Vernacular names
- Indonesia: rumbai (Bangka), pies (Lampung), pandan ayer (Moluccas)
- Malaysia: selensing, selingsing
- Philippines: gaás (Bikol), bilis (Subanon), barongis (Bagobo).
Origin and geographic distribution
Scirpodendron ghaeri is distributed from Sri Lanka through peninsular Thailand, the Nicobar Islands (Great Nicobar) and Malesia to Australia (northern Queensland), the New Hebrides and Polynesia. In Malesia it is found in Peninsular Malaysia, Sumatra (including Bangka, Simeuluë and the Mentawai Islands), Java (West and Central), Borneo, Sulawesi, the Moluccas, the Philippines and New Guinea. It is sometimes cultivated in South Sumatra.
Uses
In Indonesia (Sumatra, the Moluccas) the leaves of S. ghaeri are made into mats (e.g. for sitting, sleeping, drying of rice), bags and various small products for domestic use. In the Philippines (Leyte) they serve in the production of hats. The leaves are sometimes used together with those of Pandanus spp. In Sri Lanka and Vanuatu the leaves are used for the production of mats, in Fiji for thatching. The fruits are eaten in Samoa.
Production and international trade
No production statistics are available for S. ghaeri . Mats and bags made of S. ghaeri are traded locally in Indonesia.
Properties
The leaves of S. ghaeri look like pandan leaves, but weaving material obtained from them is apparently of lesser quality and durability. Nevertheless, S. ghaeri is specifically cultivated for mat-making in South Sumatra. No detailed information is available on the morphological, chemical and physical properties of S. ghaeri leaves.
Adulterations and substitutes
Other Cyperaceae and Pandanus spp. may be used for weaving instead of S. ghaeri .
Description
Subaquatic, low but robust, rhizomatous, perennial herb, up to 60 cm tall (but leaves much longer), in habit resembling a small pandanus, often growing in large, dense clumps. Rhizome thick, woody, prostrate but obliquely ascending at neck, 6-12 cm × 1-2.5 cm, clothed with imbricating, acute scales and their fibrous remains and bearing several robust, dark brown roots 3-5 mm thick. Stem erect, triangular in cross-section with slightly concave sides, 30-60 cm × 5-10 mm, smooth, glabrous, without nodes, leafy at the base only. Leaves numerous, arranged in 3 vertical rows, sheathed; sheath up to about 18 cm long, open, dark brown; blade oblong-plicate, drooping in the upper part, 1-4 m × 2-5 cm, coriaceous, 3-veined, margins serrulate-scabrous, apex gradually narrowing into a filiform, 3-sided, scabrous tail 15-25 cm long. Inflorescence a terminal, paniculate cluster of spikes, branched in the lower half, the lower branches in clusters of 3, short, thick and obliquely spreading; panicle dense, cylindrical to ovoid, in fruit (5-)10-20 cm × 5-7 cm; lowest 3 bracts pseudo-whorled and leaf-like, higher ones much smaller, reduced to scales in upper ones; spikes ovoid, 1-2 cm × 5-9 mm, in subsessile clusters, many-flowered; glumes ovate, 6-10 mm × 3-4 mm, many veined, subcoriaceous, spirally imbricate, each glume bearing an axillary, bisexual cyme; terminal flower of each spike with a terminal pistil (pistillate flower) surrounded by flat, spirally arranged scales each bearing an axillary stamen (staminate flower); lateral flowers strongly compressed, also with a terminal pistil but with the 2 outer scales opposite and boat shaped and the other scales flat with an axillary stamen; in the lower fertile glumes of the spike the arrangement of the flowers can be more complex; style continuous with the ovary, not thickened at base, ending in 2 or 3 stigmas; anthers linear, 3-4 mm long. Fruit drupaceous, rather variable, conical-ellipsoid, 1-1.5 cm × 1 cm, acute, with 5-10 more or less prominent and tuberculate longitudinal ribs, dusky brown, exocarp succulent becoming corky when dry, endocarp bony, black.
Growth and development
The fruits of S. ghaeri readily float away when the water rises. They are also carried off by rats who eat the corky exterior.
Other botanical information
Within the subfamily Cyperoideae , Scirpodendron Zipp. ex Kurz belongs to the tribe Hypolytreae , which also includes Lepironia L.C. Rich. , Mapania Aublet and Thoracostachyum Kurz. Scirpodendron has long been considered a monotypic genus, with S. ghaeri as the only species. In 1997, however, a second species, S. bogneri S.S. Hooper, was described from Peninsular Malaysia where it occurs in blackwater streams in inland swamp forest. It is somewhat smaller than S. ghaeri and its inflorescence has a much softer appearance due to the almost confluent spikes; its glumes are thinner and the flower scales longer and more acute.
In 1788, Gaertner described fruits of S. ghaeri as Chionanthus ghaeri , but classified them in the family Oleaceae . In 1864, Thwaites described it as a new sedge species from Ceylon: Hypolytrum costatum . In 1869 Kurz transferred this name to Scirpodendron and for a long time the species was known as S. costatum (Thw.) Kurz. In 1895 Boerlage discovered that Chionanthus ghaeri and Scirpodendron costatum were synonymous, but the new combination based on the correct basionym of Gaertner was not published until 1914 by Merrill.
S. ghaeri has stomata which tend to be tetracytic and are more irregularly distributed than in most Cyperaceae . Another distinguishing character are the wedge-shaped silica bodies, which are shared with only a few other genera of the Cyperaceae , notably Thoracostachyum .
Ecology
S. ghaeri occurs in freshwater tidal areas on clayish soils, in tidal swamp forests, transition forests behind mangroves and along river mouths, especially in locations where the water is waist deep during high tide or following heavy rainfall. In the Philippines it is sometimes found at the borders of lakes. It often forms pure stands which are impenetrable.
Propagation and planting
In cultivation S. ghaeri is propagated by means of offsets.
Husbandry
In Sumatra (Jambi and Palembang) S. ghaeri is cultivated in marshes, but usually without much maintenance.
Harvesting
In Jambi the leaves of S. ghaeri are considered suitable for weaving when they are about 3.5 m long, at 5 years after planting. The leaves are harvested by cutting.
Handling after harvest
In Palembang the prickly edges and midribs are removed and the remaining leaf halves are dried and divided into strips, which are then pulled over a piece of bamboo to make them smooth and supple. In Jambi the midribs are removed and the leaves are first split into strips before being dried in the sun for about 3 days.
Genetic resources and breeding
In the Nicobar Islands S. ghaeri is considered a rare and endangered species. No germplasm collections or breeding programmes of S. ghaeri are known to exist.
Prospects
Though S. ghaeri may be locally important, its overall role will remain limited because of the availability of species yielding higher quality material, such as Pandanus spp. Because of the artistic value of the articles made of S. ghaeri leaves, the tourist market may offer some potential.
Literature
- 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). p. 313.
- Hooper, S.S. & Simpson, D.A., 1997. A new species of Scirpodendron (Cyperaceae) with a discussion of the inflorescence in the genus. Kew Bulletin 52(3): 683-687.
- Jasper, J.E. & Pirngadie, M., 1912. De inlandsche kunstnijverheid in Nederlandsch Indië [Native arts and crafts in the Dutch East Indies]. I. Het Vlechtwerk [Wickerwork]. Boek & Kunstdrukkerij v/h Mouton & Co, 's-Gravenhage, the Netherlands. p. 34.
- 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. 435-753.
Authors
D. Darmakusuma & A.T. Karyawati
