Aleurites
Read about Aleurites in the Standard Cyclopedia of Horticulture
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Aleurites (Greek, farinose or floury). Euphorbiaceae. Tropical trees grown for the oils they yield or sometimes for shade and ornament. Leaves alternate, palmately veined, 3-5-lobed, the long petioles with 2 glands at the apex: fls. usually monoecious, in lax terminal cymes; sepals 2-3, valvate; petals 5; stamens 8-20, the inner row monadelphous; ovule in each cell of the 2-5-celled ovary: fr. large, drupaceous, with thick-shelled seeds.—Four species, with milky juice, natives of E. Asia and Pacific Isls. Jatropha and Hevea, are related genera. All of the species are cultivated in tropical countries for the drying oil derived from the seeds. These oils are similar to linseed oil, but dry quicker, harder and more waterproof but less lightproof and elastic. The seeds of A. moluccana yield 60 percent of oil (kekuna, krlun or bankul oil), which is used for burning or in varnishes. The seed or oil is also used to some extent as food and the wood is worked. The tree is grown for shade. It is said to be easily grown in the tropics up to 2000 feet altitude. It is easily propagated from seeds, which sprout in four to five weeks. The oil (wood-oil, tung-oil) of the seeds of the wood-oil trees (A. cordata, A. Fordii) is much used, especially in China and Japan, for treating woodwork, cloth, and the like, and for burning. Its importation to this country is on the increase, where it is used in varnishes and other products, paints, soaps, linoleum, and so on. A. Fordii, which is the hardier species, has been extensively introduced into the southern states by our Department of Agriculture and is reported to be doing very well. A. cordata is a fine smooth-barked tree, good for shade and will stand high temperature, but not much below freezing. A. Fordii is a very ornamental tree. The wood-oil trees are usually grown on dry, thin soil not suited to general farming. They are grown from seeds, and begin to produce nuts in three to six years. The seedlings are raised in a bed and transplanted when about a foot high or are planted where they are to stand. They may also be propagated from hardwood cuttings, which root readily. An average tree is said to yield twenty to fifty pounds of nuts with about 24 percent of oil. The oil is pressed from the seed after roasting. The seed is poisonous. See Circ. 108, U. S. Bu. PI. Ind.
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Aleurites moluccana (Candlenut) | ||||||||||||||||||
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See section Species. |
Aleurites is a small arborescent genus of plants in the tropical and subtropical regions of Asia, the Pacific and South America, belonging to the Spurge family Euphorbiaceae.
These monoecious, evergreen trees are perennials or semi-perennials. These are large trees, 15-40 m tall, with spreading drooping and rising branches.
The leaves are alternate, lobate, ovate to ovate-lanceolate with minute stipules. They are pubescent on both sides when young, but in a later stage they become glabrous.
The inflorescence consists of terminal plumes of small, creamy white bell-shaped fragrant flowers, branching from the base. The flowers are usually bisexual, with a solitary pistillate flower at the end of each major axis. The lateral cymes are staminate. There are five or six imbricate petals. The staminate flowers are mostly longer and thinner than the pistillate flowers, with 17-32 glabrous stamens in four whorls. The pistillate flowers have a superior ovary.
The fruits are rather large drupes with a fleshy exocarp and a thin, woody endocarp. They vary in shape, according to the numbers of developed locules. They contain oleiferous seeds. These seeds are poisonous.
The oil has been used as a paraffin, lubricant or as a constituent of varnish, paint or soap. It has also been used as baking oil, after removing the poisonous substances.
Some deciduous Chinese species are now classified under a separate species Vernicia.
The name Aleurites is derived from a Greek word meaning "wheaten flour", because of the appearance of the lower surface of the leaf.
Species
The most widespread species is the Candlenut (Aleurites moluccana), occurring from tropical Asia, the Pacific, from India to China and Polynesia, Australia and New Zealand. Some botanists only recognize two species, Aleurites moluccana and Aleurites rockinghamensis.
- Aleurites angustifolia - (New Caledonia)
- Aleurites cordata - (China)
- Aleurites erratica
- Aleurites fordii - varnish tree, tung tree, tung oil tree, China wood oil tree (China)
- Aleurites integrifolia - (New Caledonia)
- Aleurites javanica - (Java)
- Aleurites moluccana - Indian walnut, candlenut tree, country walnut, aburagiri, ama
- Aleurites moluccana var. floccosa - (New Guinea)
- Aleurites moluccana var. katoi - (Hawaii)
- Aleurites moluccana var. moluccana
- Aleurites moluccana var. rockinghamensis - (New Guinea, Australia)
- Aleurites montana (now Vernicia montana) - wood-oil tree, mu oil tree.
- Aleurites pentaphylla - (East Asia)
- Aleurites remyi - (Hawaii)
- Aleurites saponaria - (Philippines)
- Aleurites triloba - (Pacific)
References
- Stuppy, W., P.C. van Welzen, P. Klinratana & M.C.T. Posa. 1999. Revision of the genera Aleurites, Reutealis and Vernicia (Euphorbiaceae). Blumea 44: 73-98.