Triadica
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Chinese sebum tree ( Triadica sebifera ) in autumn in Japan |
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Triadica is a genus of plants inthe milkweed family (Euphorbiaceae). The only three Triadica species are native to eastern and southern Asia.
description
Vegetative characteristics
Triadica species grow as trees or shrubs . There is a white milky juice present. The alternate or almost constantly against arranged on the branches leaves are divided into petiole and leaf blade. There are one or two glands on the petiole. The simple leaf blade is pinnate, with the lowest pair of leaf veins forming the lower leaf margin. The leaf margin is smooth or serrated.
Generative characteristics
Triadica species are usually monoecious ( monoecious ) or sometimes dioecious ( dioecious ) separate sexes. Terminal or lateral, simple or sometimes branched spike or grape-like zymous inflorescences are formed. The bracts have two large glands at their base. The unisexual flowers always lack petals and disc. In the axes of the bracts the small, yellow flowers stand together in small bundles. The male flowers have cup-shaped, fused membranous sepals and the calyx is only indistinctly two- to three-lobed or toothed. A rudimentary gynoecum is missing. The two to three stamens are free. There is only one female flower per bract, which is larger than the male. In the female flowers, the cup-shaped calyx is usually three-part or toothed. Two to three carpels are a two- or dreifächerigen ovary grown. Each ovary compartment contains only one ovule . Most of the three styles are fused at most at their base.
Usually spherical, pear-shaped or triple capsule fruits , rarely three-chambered berries are formed. The hemispherical seeds are usually covered by a waxy aril and have a hard exocarp and a fleshy endosperm . The two cotyledons ( cotyledons ) are wide and flat.
Systematics and distribution
The genus is native to eastern and southern Asia. All three types are also found in China. Their total distribution area extends from India via Thailand and Indochina to China , Taiwan , Japan , Borneo , Celebes and the Philippines . The Chinese sebum tree ( Triadica sebifera ) is planted in many countries and is partially overgrown and is considered an invasive plant .
The genus name Triadica was published in 1790 by Loureiro in Flora Cochinchinensis , first and second editions, pp. 598 and 610. The type species is Triadica sinensis Lour ., Which is now Triadica sebifera (L.) Small . This species was earlier in the Stillingia sect. Triadica (Lour.) Baill. , Sapium sect. Triadica (Lour.) Garbage. Arg. Or Excoecaria sect. Triadica (Lour.) Müll.Arg. in DC. classified. The evaluation of Triadica as a section in different genres or as an independent genre changed frequently. The genus Triadica belongs to the tribe Hippomaneae, in the subfamily of Euphorbioideae within the family of Euphorbiaceae .
There are only three types of Triadica :
- Triadica cochinchinensis Lour. : It has the widest natural distribution of the three species. Their distribution area extends from India via Thailand and Indochina to China (also to Hubei and Zheijang), to Borneo , Sulawesi and the Philippines . It thrives in different types of secondary vegetation, even in dry locations and acidic soils up to altitudes of around 1000 meters.
- Triadica rotundifolia (Hemsley) Esser : Of the three species, it has the smallest distribution. It occurs only in the Chinese provinces of Yunnan, Guangxi, Guizhou, Hunan, Guangdong and adjacent areas in Vietnam. It is characteristic of subtropical evergreen laurel forests and was found at altitudes of around 1400 meters.
- Chinese sebum tree ( Triadica sebifera (L.) Small ): The frost-hardy species is widespread in Taiwan, in the southern parts of Japan and China (from Yunnan and Hainan to Gansu, Shandong and Henan), in Korea and Vietnam. It thrives in many forest types and different soils from dry to wet conditions and even tolerates brief flooding; it reaches heights of up to about 1700 meters.
use
Triadica sebifera is used in many ways: In Asia, the waxy coating of the seeds is used to make candles and soap . The leaves are used in medicine to treat boils . Plant parts can be used to produce biodiesel . The plant nectar is also non-toxic and therefore Triadica sebifera is popular with beekeepers as a beehive plant . Triadica sebifera is used as a decorative, fast-growing and shade-giving ornamental plant with a beautiful autumn color. Triadica cochinchinensis seeds provide similar oil / sebum, but are rarely used.
literature
- Bingtao Li & Hans-Joachim Esser: Triadica in the Flora of China , Volume 11, p. 284: Online. (Section description, systematics and dissemination)
- Hans-Joachim Esser: A Revision of Triadica Lour. (Euphorbiaceae) , in Harvard Papers in Botany , Volume 7, No. 1, 2002, pp. 17-21: PDF-Online.
Web link
Individual evidence
- ^ Rafaël Govaerts (ed.): Triadica. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 21, 2020.
- ↑ Triadica cochinchinensis from Useful Tropical Plants, accessed November 25, 2017.