Hyphaene
Doumpalme ( Hyphaene thebaica )
The doum palms ( Hyphaene ) are a mainly native to the arid regions of Africa and Arabia genus of the palm family. They are characterized by an otherwise rare palms in strong aboveground branching of the stems.
Features
The doum palms are small to large, stocky individual or group- shaped fan palms whose stems are usually multi-branched dichotomously. They are dioecious getrenntgeschlechtig ( dioecious ) and repeatedly flowering.
The leaf stalks are strongly reinforced. The leaves are induplicat and costapalmat. They remain after the death of the plant ( Marzeszenz ) and late fall under its own weight. Characteristic is the common silver staining and the absence of abaxial Hastula. The inflorescences are rather slim and stand between the sheets ( interfoliar ). The fruits are brown drupes.
From the closely related genera to Hyphaene distinguished by the following combination of characters: The fruit is shaped differently, it is extended distally, usually it is asymmetrical, rarely ovate or spherical. The seed has an irregular outline, is not grooved and has a homogeneous endosperm. The endocarp is winged and has a terminal pore.
The chromosome number is 2n = 36
Dissemination and locations
The representatives are found in the more arid regions of Africa, in the south to Natal and Madagascar. In the north, the distribution area along the shores of the Red Sea reaches on the Arab side to the Gulf of Eilat. There are also deposits on the west coast of India. Occurrence in Sri Lanka may be of human origin.
The doum palms grow mainly in arid and semi-arid regions, but the locations are always in the surface groundwater, as they grow along seasonal watercourses, on coastal sand dunes and plains and oases. Hyphaene compressa rises in East Africa up to 1400 m above sea level. Hyphaene guineensis comes in Gabon in offshore locations with high rainfall ago, is thus within the genus an exception.
Since all species are used by humans, today's distribution of the species itself does not necessarily cover with their natural: destructive use of the area may have limited accidental or intentional spreading may have expanded the area.
System
The genus Hyphaene is placed in the subfamily Coryphoideae, Tribe and subtribe Borasseae Hyphaeninae within the family Arecaceae. The genus is monophyletic. Their sister group is Medemia.
We have published numerous species names, but there should be relatively few species. In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following types are recognized:
- Hyphaene compressa
- Hyphaene coriacea
- Hyphaene dichotoma
- Hyphaene guineensis
- Hyphaene macrosperma
- Hyphaene petersiana
- Hyphaene reptans
- Hyphaene thebaica
Use
All doum palms are locally of great economic importance, especially in subsistence agriculture. The leaves are used for thatching and for the production of fibers for weaving. The offspring cone is used for tapping palm wine. The wood is often used. The fruits provide an edible mesocarp, endocarp and the unripe fruit is edible. More importantly, the endocarp of ripe fruit, which is used as a vegetable product ivory. All parts of the palm trees, unless otherwise available, serve as fuel.
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. 314ff.