Eugeissona triste (PROSEA)
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Introduction |
Eugeissona triste Griff.
- Protologue: Calcutta Journ. Nat. Hist. 5: 101 (1845).
- Family: Palmae
- Chromosome number: 2n= unknown
Vernacular names
- Bertam, bertam palm, mountain nipa (En)
- Malaysia: bertam, beltop (Sakai), cembag (Semang)
- Thailand: chaak khao, chaak cham (peninsular).
Origin and geographic distribution
Bertam is endemic to Peninsular Malaysia and peninsular Thailand. In Peninsular Malaysia it is very common and considered a forest weed.
Uses
The leaves of bertam are widely used in Peninsular Malaysia for making roof thatch ("atap"). The Orang Asli of Malaysia use the leaves not only for making roofs, but also for house partitions, screens and baskets. The petiole and midrib, with the leaflets removed, serve as cross-beams in traditional house-building. Flattened petioles or strips cut from the outer portion may be woven into mats for walls of traditional Malay houses. Strips of the petiole are also used to make sun-blinds and fish traps. Fibres may be beaten out of the petioles and twisted into strips for necklaces.
The petiole and midrib are made into fishing poles and clothes-hangers. Ornamental walking sticks are made from the petioles and the roots. The petioles or strips of their outer layers are used by traditional Chinese communities as a supporting material for the paper models of figures and other items such as lanterns, houses, effigies, horses, cars and television sets used in funerals and memorial ceremonies. A portion of the inflorescence is sometimes used as a ceremonial knife for cutting the umbilical cord at birth. The midrib of the leaflet and the epidermis of rachis and petiole are made into darts for blowpipes. The pith of the petiole provides the base of these darts and root portions serve to close the bamboo tubes holding dart poison. The roots are made into flooring material for houses.
Some sago may be obtained from the stem and inflorescence, and the young fruits are eaten. The flower buds exude drops of sugary nectar when cut. This sugary solution is tapped and drunk, either fresh or fermented into an alcoholic drink. Fruits and unopened inflorescences are cut, dried and lacquered to make ornamental and decorative objects sold to tourists. Bertam is sometimes planted as an ornamental.
Production and international trade
No statistics on production and trade of bertam are available. In Perak (Malaysia) petioles are collected and sold to Chinese funeral parlours. Some products used by Chinese communities may be sold in Singapore or Brunei. The demand and utilization of bertam is much lower than the supply available.
Properties
To remain waterproof, roofs to be thatched with bertam need to be steeper than those thatched with nipa palm ( Nypa fruticans Wurmb). At a pitch of 50and laid closely, bertam roofs have been estimated to last for 4-5 years. No information is available on the morphological, physical and chemical properties of the fibre.
Adulterations and substitutes
Substitutes for E. triste as a source of thatch are mainly members of the Palmae ( Borassus flabellifer L., Cocos nucifera L., Metroxylon sagu Rottboell, Nypa fruticans ), Pandanaceae ( Pandanus spp.) and Gramineae ( Imperata spp., Miscanthus spp.).
Description
A robust, acaulescent, rhizomatous, spiny, hapaxanthic palm, up to 10 m tall, growing in clumps up to about 3 m in diameter, surrounded by a thick cover of long persisting dead leaves. Rhizome creeping, 1-1.5 m long, 10-20 cm in diameter, extremely woody and hard, branching at short intervals, with a shoot at the end of each branch, covered with slender feeder roots and deeper penetrating, thicker anchorage roots. Leaves numerous, pinnate, erect to ascending; sheath 60-90 cm long, deeply split, densely covered with silver to brown indumentum, armed with black, needle-like spines 2-5 cm long; petiole 3-5 m long, indumentum and spines like those on sheath; midrib 3-4.5 m long, spines as on petiole; leaflets arranged regularly, up to 55 on each side of midrib, oblong, 45-70 cm × 3-4 cm, with scattered spines on midrib. Inflorescence interfoliar, panicle-like, narrow-elongate, erect, up to 3 m long; peduncle up to 1 m long, rachis up to 2 m long with 15-25 erect, adpressed branches up to 30 cm long, which themselves branch again, and all branches covered by numerous, brown, overlapping bracts which are tubular at base; flowers paired, terminal on short branches 5 cm long (rachillae) which end in a cupule, a symmetrical male flower developing first, later pushed off by a lopsided bisexual flower that is protandrous and longer than the male flower; calyx tubular, with 3 teeth at apex; corolla tubular, 5 cm long, 3-lobed, connate in lower third enclosing the ovary in bisexual flowers, lobes long and narrow, sharply pointed, woody, brown; perianth falling in male, persisting in bisexual flowers; stamens 20-25, inserted in corolla just above the ovary or about in the middle, filaments short, anthers narrow, elongate, pollen brown-purple; ovary (absent in male flowers) 3-chambered but partitions not joined, ovules 3; stigma on top of ovary, pyramidal, hard. Fruit a spindle-like drupe, up to 10 cm × 5 cm, covered with small irregularly arranged dark brown scales with frilled margins; mesocarp somewhat corky and fibrous; endocarp stony, with 3 big and 3 small flanges penetrating into the fruit cavity (and into the endosperm of the seed), forming symmetrical, incomplete partitions. Seed basally attached, single, filling the fruit cavity, closely adhering to the endocarp; seedcoat thin, dry; endosperm homogeneous, hard, embryo basal.
Growth and development
At germination of bertam seed a cotyledonary stalk grows about 15-20 cm vertically down into the soil, after which it bends sharply. At the bend a leaf sheath pushes through the apex of the stalk and grows up to the soil surface, where the first leaf emerges from the sheath and rises above the ground. Temporary roots emerge from the stalk where it starts in the seed, whereas the first permanent root emerges at the bend. It has been suggested that this type of germination ("cryptogeal germination") is to get the seedling into the ground through the litter layer.
Germination takes at least 3 months, and the first and second leaves appear on average 5 and 9.5 months after sowing, respectively. The time between leaf appearance and complete unfurling of the leaflets is 9-14 weeks. At 3.5 years after germination, bertam planted in Kepong (Malaysia) was only about 1.5 m tall with 10 leaves, and clump formation had not yet begun.
Bertam grows according to Tomlinson's architectural model, characterized by the repeated development of equivalent orthotropic modules in the form of basic branches; growth of the modules is usually continuous, sometimes rhythmic. Bertam produces horizontally growing, sympodially branched, hard and woody rhizomes, with short vertical branches carrying the leaves and inflorescences. Dead leaves do not abscise neatly, but tend to flop down and rot while still attached to the stem.
In contrast to most other palms but in common with Corypha utan Lamk and Raphia P. Beauv. flowering is hapaxanthic: upon flowering the stem ceases to grow vegetatively and eventually dies. The plant continues to grow through the rhizome, which develops new shoots. Bertam has both male and bisexual flowers, with the male ones developing first and reaching maturity at 4-5(-7) months after bud initiation. Within 2 weeks after male flowering the hermaphrodite flowers protrude, reaching maturity 3 months later. The pollination system is not well known, but in view of the flower morphology and the wind-still rainforest habitat, self-pollination is unlikely and insects probably play a more important role in pollination than wind. Fruits take about 6-7 months to mature. Wild pigs, squirrels and rats eat from the fruits and probably play a role in the dissemination of the seed.
Other botanical information
E. triste is the type species of Eugeissona Griff. The genus name is based on the suitability of E. triste for thatching, from the Greek words "eu", meaning "good", and "geisson", meaning "a tile, cornice of a roof". In many literature sources E. triste can also be found as E. tristis , but Griffith published this taxon as E. triste . Bertam shows considerable morphological variation, e.g. in the size of its leaves and inflorescences; this may be due to ecological variations as well as to some genetic variation. In Johor (Malaysia), for instance, a form with more slender petioles, narrower leaflets, and smaller inflorescences is found in seasonally swampy forests and on some mountain slopes.
Ecology
Bertam is found in a wide range of forest types, from swamp margins to hilltops. It is most abundant on hill ridges up to 1000 m altitude, where it dominates the undergrowth after logging and prevents regeneration of commercially important timber trees such as Shorea curtisii Dyer ex King. Bertam is found on almost all hill-forest soils, from clays to coarse sandy loams, but thrives in well-drained habitats. Bertam is most common on the western coast of Peninsular Malaysia, including the western flanks of the main range. In the eastern part it is much more scattered; nevertheless it is locally just as abundant as in the western part. The Malaysian Forest Department is trying to find a way of preventing forests from becoming bertam groves after logging instead of regenerated forest. Although considered a forest weed, bertam may serve an important auxiliary function on slopes, controlling soil erosion and increasing soil stability. Cut leaves rot slowly and blanket the soil for a long time.
Propagation and planting
Bertam can be propagated by seed, but is not planted deliberately. Material for thatching and other purposes is obtained from wild stands.
Husbandry
Bertam grows well without much care or attention. In fact, more research has been carried out on the control of bertam as a weed than on its cultivation. To permanently eradicate a bertam clump the rhizome needs to be killed, for instance using systemic herbicides such as hexazinone. However, no effective and economic control method has been found that does not have side-effects on neighbouring trees.
Diseases and pests
Bertam is not known to be seriously affected by any disease or pest.
Harvesting
As many long spines are present on the leaf stalks as well as on both sides of the leaf blades, great care must be taken when harvesting bertam leaves. If the whole leaf is required, spines are removed from a small portion of the leaf base, to make handling easier. If only the leaf stalks are required, all the spines and leaflets are removed by scraping with a sharp knife. The clean leaf stalks are then tied in bundles and carried out of the forest.
Yield
No statistics are available on yield of bertam leaves, fruits or other products.
Handling after harvest
Bertam leaves are processed while still fresh, because dried leaves are too brittle to work. Similarly, bertam petioles and strips of petioles are best used while moisture is still present in the tissues. Dried strips of petioles are soaked in water for some time before being used, so they are not too brittle.
Genetic resources and breeding
Bertam does not seem to be threatened with extinction. There are no known germplasm collections or breeding programmes or experiments.
Prospects
It is very unlikely that bertam will become economically important in Malaysia or Thailand. For people living in the forest or forest fringes, however, bertam will remain a useful forest resource with multiple uses. Though usually considered a weed by foresters, it may play a role in the prevention of erosion.
Literature
1 Fong, F.W., 1978. Autecological studies on Eugeissona tristis. The Malaysian Journal of Science 5: 93-108.
- Hodel, D.R. (Editor), 1998. The palms and cycads of Thailand. Kampon Tansacha, Nong Nooch Tropical Garden, Thailand. pp. 96-98.
- Manokaran, N., 1979. Age of the bertam palm, Eugeissona tristis Griff., at the tenth leaf stage. The Malaysian Forester 42(2): 125-129.
- Ong, H.C., 1986. Ecology, resource utilization and ethnobiology of the Temuan at Ulu Langat, Selangor. PhD thesis, Department of Botany, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. 5 Uhl, N.W. & Dransfield, J., 1987. Genera palmarum: a classification of palms based on the work of Harold E. Moore, Jr. The L.H. Bailey Hortorium & the International Palm Society. Allen Press, Lawrence, Kansas, United States. pp. 241-243. 6 Whitmore, T.C., 1973. Palms of Malaya. Oxford University Press, Kuala Lumpur, Malaysia. pp. 58-61.
Authors
H.C. Ong
