Borassus
Borassus is a native to Africa and Asia palm genus.
Features
The representatives are large, tree-shaped, single -stemmed and reinforced fan palms. They are dioecious getrenntgeschlechtig ( dioecious ) and repeatedly flowering. The trunk is massive and covered in the upper part with dead leaves. This fall off later and leave annular wide leaf scars. The leaves have stalks with spiny margins. The leaf blade is costapalmat ( the clearly pronounced midrib extends for some distance into the leaf blade into it ), and has on the top and underside, a Hastula. The fruits are large.
From the closely related genera is Borassus distinguished by the following combination of characters: There are numerous male flowers that are winding of 30 to 70 flowers. There are numerous male flowers inflorescence -bearing axes ( Rachillae ). There are six stamens per flower. Per fruit three seeds are usually formed, these are wider than lobed thick and weak deep. The thick endocarp (stone core ) is not deeply lobed.
The chromosome number is 2n = 36
Dissemination and locations
The genus is represented in Africa, Madagascar, India, Southeast Asia and in the drier areas times Parisiens to New Guinea and Australia. It is thus one of the most widespread palm genera. Borassus flabellifer can rise to heights of 500 to 800 m, but also occurs on riverbanks. But most often it grows in deep sand plains near sea level, where it is exposed to wind and sun. Borassus aethiopum grows in open secondary forests and savannas.
System
The genus Borassus is placed in the subfamily Coryphoideae, Tribe and subtribe Borasseae Lataniinae within the family Arecaceae. The genus is monophyletic. Their sister group is Borassodendron.
In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following types are recognized:
- Borassus aethiopum
- Borassus akeassii
- Borassus flabellifer
- Borassus heineanus
- Borassus madagascariensis
Type species is Borassus flabellifer L. The name is derived from supposedly borassos from, a designation for immature inflorescences of date palms. Why Carl Linnaeus chose this name is unclear.
Use
Borassus flabellifer is one of the most heavily used palm species: the wood is used as timber, the inflorescences are tapped for the production of syrup, sugar and alcohol.
Documents
- John Dransfield, Natalie W. Uhl, Conny B. Asmussen, William J. Baker, Madeline M. Harley, Carl E. Lewis: Genera palmarum. The Evolution and Classification of Palms. Second edition, Royal Botanic Gardens, Kew 2008, ISBN 978-1-84246-182-2, pp. 329-331.