Keim, A.P. & Dransfield, J. 2012. Kew Bulletin 67: 127. https://doi.org/10.1007/s12225-012-9356-6
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Morphology
General
Habit
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Large palm
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Morphology
Trunk
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Trunk c. 15 m high, c. 15 cm diam. (dbh), internodes c. 8 cm
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Morphology
Reproductive morphology
Inflorescences
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Inflorescence spreading, branching to 2 orders, massive, rather glabrous or with red-brown tomentum, c. 1.5 – 2 m long; prophyll persistent, disintegrating into fibres, c. 45 × 12 cm; peduncle c. 75 – 100 cm long, glabrous or with white indumentum; peduncular bract one, woody, persistent, c. 2 – 2.5 m long, 10 – 11 cm wide near the base; rachis c. 75 – 100 cm long; first order branches c. 41 – 55 cm long, rachillae bract c. 3 – 4 mm long; rachillae conspicuously slender, branching at convergent angle, conspicuously straight, c. 30 – 42 cm long, bearing 100 – 154 flower clusters, bearing triads arranged in proximal c. ⅔ up to 2.5 cm from distal, triads c. 7 – 15 mm distant, the basal c. 1 – 1.7 cm devoid of flowers, sometimes pistillate flowers found in the first order branch
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Morphology
Reproductive morphology
Flowers
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Pistillate flowers with calyx of 3 united sepals, c. 0.5 – 0.7 mm long; corolla with 3 free petals, c. 3.5 – 4 mm long, 3 – 4 mm wide; staminodes 6, unequal, 2 being different, larger with hooked tip, c. 10 mm long, otherwise c. 1.2 – 2 mm long; gynoecium dark-brown, c. 3.5 – 4 mm long; stigma with 3 elongate lobes
Staminate flowers with calyx of 3 united minute sepals; corolla with 3 free petals, c. 5 – 6 mm long, 2 – 2.5 mm wide; stamens 6, filaments free, dark-brown, c. 0.5 – 0.75 mm long, anthers elongate-lanceolate, pale creamy yellow, always free, c. 2.5 – 3 mm long; pistillode absent
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Morphology
Reproductive morphology
Fruits
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Fruits globose or bilobed, c. 4.5 – 5 cm diam., dull green when young, yellowish green when mature; epicarp smooth, thin; mesocarp fibrous, 1 – 1.5 mm thick; endocarp thinner, hard, red-brown; endosperm white, c. 3 – 4 cm diam., c. 2.5 cm thick, with a hollow inside, c. 1 – 1.5 cm wide
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Morphology
Reproductive morphology
Seeds
Embryo
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Embryo placed below middle line of seed
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Morphology
Leaves
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Eophyll bifid.
Leaves c. 15 in the crown, spirally arranged, densely covered with red-brown tomentum, c. 4 – 5 m long; leaf-sheath c. 80 cm, 8 – 10 cm wide, adaxial surface glabrous, abaxial surface with dense red-brown tomentum, margins disintegrating into fibres, straight, c. 5 cm long; petiole c. 1 m long; rachis 2.2 – 3.2 m long, c. 3 cm diam. in the middle; leaflets elongate-lanceolate, regularly arranged leaflets held in one plane, c. 100 in total number, leaflets c. 5.5 – 6 cm distant, c. 1.05 – 1.5 m long, 6.8 – 7 cm wide, adaxial surface dark green, glabrous, with red-brown tomentum on the midrib, midrib robust, other less thick; abaxial surface densely covered with white indumentum, red-brown tomentum on the margin, midrib robust, other ribs less thick
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Distribution
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Widespread in almost every part of Western Malesia and slightly beyond the boundary with Indochina floral region (restricted only in southern part of Thailand). Area of distribution covers Malay Peninsula, Singapore, Sumatra, West Java, Anambas Islands, Karimata Islands Group, West Kalimantan and Sarawak. The species so far has never been recorded in the Philippines, Sulawesi and Sabah. Map 10.
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Ecology
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Lowland humid evergreen tropical rainforest from 0 to about 600 m above sea level. In some parts of Sumatra and Borneo sometimes found in heath forest (‘kerangas’).
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Conservation
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Least concern (LC). On a global scale this species is widespread and often abundant in, for example, Peninsular Malaysia and South Thailand. However, at the local level it may be seriously threatened; for example, in Java it is on the verge of extinction.
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Note
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Growing in the forest.
Orania sylvicola is the second-most widespread species after O. palindan. This species is also known to inhabit a wide range of habitats, from humid lowland rainforests with rich soil to heath forests with very poor sandy soil. O. sylvicola is commonly found from coastal areas up to about 600 m above sea level.
In Southern Thailand — around Tamben Kao Panom, Kerr 18802 — it has been reported from 1100 m. In Malay Peninsula O. sylvicola is found throughout the peninsula and on the adjacent island, Tioman.
In Singapore O. sylvicola used to be found on mainland Singapore and a small offshore island (Ubin). However, this is based on reports and specimens collected by Ridley in 1891 (see Ridley 1900) at a time when a large part of Singapore was still covered with lowland tropical rainforest. The presence of O. sylvicola in Singapore and the surrounding islands has never been reported again.
In Sumatra O. sylvicola is found throughout the island but mostly in the North and Central part of the island (i.e. the Provinces of North Sumatra and Jambi). Dransfield (1974) reported O. sylvicola in an area between Jambi and Bangko growing in lowland grassland (‘alang-alang’). In South Sumatra it has been reported growing in great numbers in heath forest (‘kerangas’) developed on very poor sandy soil just about 200 km from the coast (see Dransfield 1972). Apart from these two reports O. sylvicola normally grows in lowland forest on rich soil. So far no species of Orania has been reported from the northernmost part of the island (Aceh). As in Sumatra, in Borneo O. sylvicola is also found scattered throughout the island — mostly in the western part, but it is absent from Sabah.
In Borneo O. sylvicola is also found in both lowland forest on well-drained soil (sometimes also in sandstone based soil as in West Kalimantan) and occasionally in heath forests (‘kerangas’) with less rich soil as in some parts of Sarawak (see Dransfield 1984).
In Java O. sylvicola is restricted to the western part only. Nowadays this species can be seen only in the Dungus Iwul Nature Reserve, Jasinga, West Java. Another locality in West Java where O. sylvicola was once found is Pancoran Mas Nature Reserve-Depok (Backer & Bakhuizen van den Brink 1968). It was still there until at least the early 1970s (Dransfield 1998 pers. comm.). Unfortunately, when AK visited the place, O. sylvicola was no longer present. O. sylvicola has never been reported further east from West Java. Although there is another species that possesses the unequal staminodes, O. longistaminodia, several characters distinguish O. sylvicola from O. longistaminodia (Table 22).
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Vernacular
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ibul (Malay-Peninsula dialect), iwul (Sundanese), kayu baluhur (Malay-Asahan and Padang Sidempuan dialects), pon (Thai-Kao Panom dialect), kapun (Thai-Kao Salaw dialect), lee-boy (Thai-Thalae Ban dialect).
