Phoenix (plant)
The date palm ( Phoenix) are a native in the Old World Palm genus. Characteristic are the converted to spikes lower leaflets of the pinnate leaves. Date palms grow mainly in dry areas and include 14 species. Economically important are the fruit of the date palm rights (Phoenix dactylifera ).
- 4.1 Notes and references
Features
The representatives are dwarf or creeping, to large upright, reinforced palms. They are single or multi-stemmed, dioecious and perennial plants. The trunk is often shrouded by the spirally arranged leaf bases.
The chromosome number is 2n = 32, 36
The leaves are (folded V -shaped) induplikat, feathered and wither before the fall. The leaf sheath forms a fibrous network. The petiole is short or well developed. At the top ( adaxial ) he is grooved to flat or ribbed, the lower ( abaxial ) is rounded. The rachis is long, gradually narrowing, adaxial round or flat. It ends with a leaflet. The leaflets are simply folded, pointed, are regularly or grouped. The lowest are converted into thorns and are called Akanthophylle. The veins are parallel, the midrib on the underside usually clearly visible. The leaves often carry scales, sprouting leaves are often provided with a brown, flaky Indument and / or wax.
Inflorescences
The inflorescences are between the leaves and are simply branched. Male and female inflorescences are similar. The peduncle is flattened, short to long. In female inflorescences he often extended after fertilization of the flowers. The cover sheet is often rod-shaped, sometimes zweiklappig. It is zweikielig, bald or fuzzy hairy. Other bracts are inconspicuous. The inflorescence axis is flattened and usually shorter than the stem. The side axes are unbranched, numerous and often stand in groups along the helical axis. On the lateral axes are spirally arranged triangular bracts, in whose armpit each a single flower sits.
Flowers and Fruit
The male flowers have three intergrown sepals that are fused together into a shallow cup. The three petals are pointed or rounded and substantially longer than the calyx. There are usually six stamens, rarely three or nine. Their stamens are short, erect, the anthers are straight and open laterally ( latrors ). A stamp rudiment is missing or consists of three abortive carpels, or is a small, trilobal Rest The pollen grains are ellipsoidal, bisymmetrical or slightly asymmetrical. The germ is opening a distal sulcus. The longest axis of 17 to 30 micrometers long.
The female flowers are spherical. The three sepals are fused together into a three-lobed cup. The petals overlap each other, are clearly annoyed and at least twice as long as the calyx. There are usually six staminodes. The three carpels are not fused together. They are ovate, terminating in a short scar. The ovule is attached to the base of the adaxial carpel and is anatrop.
The fruit usually develops from only one carpel. It is ovate to oblong, the scar remains apically. The exocarp is smooth, the mesocarp fleshy and endocarp membranous. The seed is oblong, the endosperm is homogeneous, rarely furrowed ( at Phoenix anadamensis ). The primary leaf is undivided and narrowly lanceolate.
Dissemination and locations
The genus is the Atlantic islands off Africa on the whole of Africa including Madagascar, in the north of Crete, from southern Turkey through the Middle East, India to Hong Kong, Taiwan, the northern Philippines, in the south to the Malay Peninsula and North Sumatra widespread.
Most species grow in semi-arid regions, but always near rivers, oases or sufficient groundwater. Some species grow in areas of the tropical monsoon. Phoenix paludosa grows landward edge of mangrove forests. Phoenix roebelenii is a Rheophyt on the Mekong, that grows in rivers.
System
The genus Phoenix alone forms the tribe Phoeniceae within the subfamily Coryphoideae. Their sister group is not secured, several works point to a close relationship with the tribes Trachycarpeae, Sabaleae and Cryosophileae.
In the World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew, the following types are recognized:
- Phoenix acaulis
- Phoenix andamanensis
- Phoenix atlantica
- Phoenix caespitosa
- Canary Island date palm (Phoenix canariensis)
- Real date palm (Phoenix dactylifera )
- Phoenix loureiroi
- Mangrove date palm (Phoenix paludosa )
- Ceylon Date Palm (Phoenix pusilla )
- Senegalese date palm (Phoenix reclinata )
- Pygmy date palm (Phoenix roebelenii )
- Cliff Date Palm (Phoenix rupicola )
- Silver Date Palm (Phoenix sylvestris)
- Cretan Date Palm (Phoenix theophrasti )
The genus name Phoenix is the Latinized spelling of the ancient Greek name for date palm or palm general. The name is part of several other generic names of palms.
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. 242-245.