Intsia bijuga, commonly known as Borneo teak, ipil, Johnstone River teak, and kwila, amongst many other names, is a species of tree in the flowering plant family Fabaceae, native to coastal areas from east Africa, through India and Southeast Asia to Australia and the western Pacific. It is most commonly found in coastal forests.
| Intsia bijuga | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Fabales |
| Family: | Fabaceae |
| Genus: | Intsia |
| Species: | I. bijuga
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| Binomial name | |
| Intsia bijuga | |
| Synonyms[2][3][4] | |
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23 synonyms
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Description
editIntsia bijuga is an evergreen tree that is usually about 25–35 m (82–115 ft) tall but may reach 50 m (160 ft), a trunk diameter between 60 and 125 cm (24 and 49 in), and buttresses up to 4 m (13 ft) tall and 2 m (6 ft 7 in) wide. The compound leaves are arranged spirally on the twigs, and usually have four broadly oval-shaped leaflets, each measuring up to 18 cm (7.1 in) long by 12 cm (4.7 in) wide.[5][6][7][8]
The inflorescences are terminal and carry many bisexual flowers (i.e. flowers that have both male and female parts). Only one petal is fully developed and is up to 3 cm (1.2 in) long; it is initially red and turns pink or red with age. The fruit is a rather flat woody pod measuring between 10–28 cm (3.9–11.0 in) long and 4–8 cm (1.6–3.1 in) broad, with up to 8 disc-shaped seeds about 3 cm (1.2 in) diameter and 1 cm (0.39 in) thick.[5][6][7][8]
Phenology
editIn Australia, flowering occurs from December to May.[9]
Taxonomy
editThe species was first described as Macrolobium bijugum by the English botanist Henry Thomas Colebrooke in 1819, and was transferred to the genus Intsia by the German botanist Carl Ernst Otto Kuntze in 1891.[10]
Etymology
editThe derivation of the genus name Intsia is uncertain,[11] but it has been suggested it may come from the Malayalam name for Acacia intsia.[7] The species epithet bijuga is from the Latin words bi (two) and jugus (paired), and is a reference to the (usually) two pairs of leaflets in the compound leaf.[9]
Vernacular names
editDue to the wide distribution of this species, spanning many different language and cultural areas, there are many common names for this tree. Some of these names are Borneo teak, intsia, Johnstone River teak, Moluccan ironwood, Pacific teak, scrub mahogany and teak in English; and bendora, ifit, ipil, kayu besi, kwila, melila, merbau asam, merbau ayer, merbau ipil, tashiro-mame, and vesi in other languages across its range.[7][9][12][13]
Distribution and habitat
editThe natural range of Intsia bijuga is, in broad terms, the Indo-Pacific region. It is native to Tanzania in Africa; the Chagos Archipelago, Madagascar, Mauritius and the Seychelles in the western Indian Ocean; Bangladesh, India and Sri Lanka in the Indian subcontinent; Andaman Islands, Cambodia, Myanmar, Nicobar Islands, Thailand and Vietnam in Indo-China; Taiwan in the South China Sea; Borneo, Java, Malaysia, Maluku, the Philippines, Sulawesi and Sumatra in Malesia; the Bismarck Archipelago, New Guinea and the Solomon Islands in Papuasia; the Northern Territory and Queensland in Australia; and the Caroline Islands, Fiji, the Marianas, the Marshall Islands, New Caledonia, Palau, Samoa, Santa Cruz Islands, Tonga and Vanuatu in the western Pacific Ocean.[2][5][7][12]
The species is mostly coastal and inhabits beach forest and the upper reaches of mangrove forest, but it can also be found in rainforest and may even occur up to 600 m (2,000 ft) altitude.[5][7][9]
Uses
editThis section needs additional citations for verification. (February 2024) |
The bark and leaves of the ipil are used in traditional medicines. The tree's timber, called kwila (taal in the Philippines, merbau in Australia, vengai in Tamil Nadu and South India), is a very durable and termite-resistant wood, making it a highly valued material for flooring and other uses. The wood can also be used to extract a dye. The tree can contain a "gold" fleck that runs through the grain, considered to be attractive by some. Due to extensive logging of the tree, it is endangered in many places in Southeast Asia, and almost extinct in some.[14] Extensive amounts were purchased for the venue of the 2008 Summer Olympics in China, which is the largest importer of the wood.[15] The wood is used for flooring in U.S. and European markets where it is commonly sold under different names. Both licensed and unlicensed mills harvest the wood.
Illegal logging
editAccording to Greenpeace large amounts of ipil timber sourced from illegal logging is being imported into China where there are lax import rules. Greenpeace are targeting users in Western countries in order to halt the trade in ipil wood. Greenpeace claimed in 2007 that at the current rate of logging "the species will be virtually wiped out in the next 35 years".[15]
In New Zealand, where the ipil wood is known as kwila, attempts have been made to stop it from being imported. In 2008 retailers were divided in whether the sale of kwila should be banned. Jim Anderton, who was the Minister in charge of the Ministry of Agriculture and Forestry at that time, did not support a ban and instead he left it up to consumer choice.[16]
Symbolism
editIntsia bijuga is the official tree of the United States territory of Guam. No longer abundant since World War II, it is illegal on Guam to cut live ifit trees. It remains the most popular wood for local carvers.[17]
Gallery
edit-
Intsia bijuga (ifit) flower cluster. University of Guam, Mangilao, Guam -
Intsia bijuga open seed pod. University of Guam, Mangilao, Guam
_flower_cluster._University_of_Guam,_Mangilao,_Guam.jpg)
References
edit- ^ Barstow, M. (2020). "Intsia bijuga". IUCN Red List of Threatened Species. 2020: e.T32310A2813445. doi:10.2305/IUCN.UK.2020-3.RLTS.T32310A2813445.en. Retrieved 15 October 2024.
- ^ a b c "Intsia bijuga (Colebr.) Kuntze". Plants of the World Online. Royal Botanic Gardens, Kew. 2024. Retrieved 15 October 2024.
- ^ "Intsia bijuga var. bijuga". Plants of the World Online. Royal Botanic Gardens, Kew. 2024. Retrieved 15 October 2024.
- ^ "Intsia bijuga var. retusa (Kurz) Sanjappa". Plants of the World Online. Royal Botanic Gardens, Kew. 2024. Retrieved 15 October 2024.
- ^ a b c d F.A. Zich; B.P.M Hyland; T. Whiffen; R.A. Kerrigan (2020). "Intsia bijuga". Australian Tropical Rainforest Plants, Edition 8. Commonwealth Scientific and Industrial Research Organisation (CSIRO). Retrieved 15 October 2024.
- ^ a b "Intsia bijuga (vesi)" (PDF). Agroforestry. Agroforestry Net, Inc. Retrieved 7 April 2021.
- ^ a b c d e f "Intsia bijuga (Colebr.) Kuntze". Flora and Fauna Web. Singapore Government. Retrieved 15 October 2024.
- ^ a b "PNGTreesKey - Intsia bijuga Kuntze". www.pngplants.org. Retrieved 15 October 2024.
- ^ a b c d Ross, J.H.; Kodela, P.G. (2022). Kodela, P.G. (ed.). "Intsia bijuga". Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. Retrieved 15 October 2024.
- ^ "Intsia bijuga". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew. 2024. Retrieved 15 October 2024.
- ^ Ross, J.H. (2022). "Intsia". Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. Retrieved 15 October 2024.
- ^ a b "Intsia bijuga". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 15 October 2024.
- ^ "Wood properties and uses of Australian timbers - Kwila". Business Queensland. Queensland Government. Retrieved 15 October 2024.
- ^ "Ipil - Intsia bijuga - Family Leguminosae". Wild Singapore. Archived from the original on 18 May 2006.
- ^ a b Bristow, Michael (6 July 2007). "China trade threatens tropical trees". BBC.
- ^ Gibson, Eloise (18 August 2008). "Stores divided over calls to ban kwila". New Zealand Herald. Retrieved 26 June 2010.
- ^ Wescom, Robert W. (19 March 2021). "Guam Trees: Ifit". Guampedia. Retrieved 6 April 2021.
Further reading
edit- F.A. Zich; B.P.M Hyland; T. Whiffen; R.A. Kerrigan (2020). "Intsia bijuga". Australian Tropical Rainforest Plants, Edition 8. Commonwealth Scientific and Industrial Research Organisation (CSIRO). Retrieved 5 March 2021.
- Sze Pang Cheung; Tiy Chung; Tamara Stark (17 April 2007). "Merbau's Last Stand" (PDF). Greenpeace International, Amsterdam.
- Sihite, Jamartin (August 2005). Bintuni Bay Nature Reserve Management Plan - Irian Jaya Barat Province 2006-2030 (PDF). The Nature Conservancy. ISBN 978-979-97700-3-5. Archived from the original (PDF) on 30 September 2011. Retrieved 22 March 2007.
External links
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Media related to Intsia bijuga at Wikimedia Commons
Data related to Intsia bijuga at Wikispecies- CIRAD Forestry Department — timber data
