Khaya ivorensis

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Khaya ivorensis
Acajou d'Afrique dans le jardin du père Gillet à Kisantu.jpg

Khaya ivorensis

Systematics
Rosids
Eurosiden II
Order : Sapindales (Sapindales)
Family : Mahogany (Meliaceae)
Genre : Khaya
Type : Khaya ivorensis
Scientific name
Khaya ivorensis
A.Chev.

Khaya ivorensis is a species of the genus Khaya withinthe mahogany family (Meliaceae). Their natural range is in tropical Africa . The wood , like that of some other related species, is known as the trade name African mahogany, traded and used in manyways.

description

Appearance and foliage leaf

Khaya ivorensis grows as a mostly evergreen , large tree that reaches heights of 40 to over 50 meters. Khaya ivorensis grows relatively quickly. In drier areas, Khaya ivorensis is deciduous, then the new leaves develop from September to November, but they unfold before the old leaves fall.

The straight tree trunk can be unbranched up to a height of 30 meters and has a chest height diameter (DBH) of up to 2 meters. Well-developed buttress roots are found on old specimens . The bark on old branches and trunks is rough, thick and reddish-brown with a bitter taste. The treetop is spread out.

The leathery and bare leaves , arranged alternately and spirally on the branches, are divided into a petiole and a leaf blade. The leaf blades are unpaired pinnate with up to seven pairs of leaf pinna. The stem of the leaves is up to 4 centimeters long, the leaflet stalks up to 1 centimeter. The dark green leaflets are 7.5 to 14 centimeters long and 2.5 to 5.5 centimeters wide and elliptical to elongated with an abruptly pointed upper end; these tips are particularly long and noticeable in young plants.

Inflorescence and flower

Khaya ivorensis is single sexed ( monoecious ). The fragrant flowers appear hermaphroditic, but are functionally unisexual. The flowering period extends from July to January, but most specimens bloom from September to December. Many flowers stand together in lateral, panicle inflorescences at the branch ends . The relatively small, whitish, flowers are five-fold with a double flower envelope . The stamens are up to 6 millimeters long, urn-shaped tube, fused with small tips, in the female flowers staminodes with antherodes are formed. The multi-chamber ovary is above and the stigma is disc-shaped, the male flowers have a pestle. There is a discus .

Fruit and seeds

The round, woody-leathery and brownish capsule fruit opens with five flaps. The 7.5 to 8.5 centimeters long and 2.5 to 4 millimeters thick fruit flaps are thinner than those of Khaya grandifoliola . The flat seeds have a diameter of 2.5 centimeters and are short-skinned all around. The striking fruits ripen between February and May; they open and release their roughly 15 seeds, but remain on the tree for months.

ecology

The diaspores are the seeds that are spread by the wind but fall to the ground not far from the mother tree.

Occurrence and endangerment

The natural range of Khaya ivorensis is in tropical Africa : Cameroon , Gabon , Ivory Coast , Liberia , Ghana , Nigeria and Angola .

It thrives in different habitats , but is most common in moist, undestroyed evergreen forests .

Khaya ivorensis occurs at altitudes from 0 to 450 meters. Khaya ivorensis thrives at average annual temperatures of 24 to 27 ° C and annual rainfall of 1600 to 2500 mm.

In the IUCN Red List , Khaya ivorensis is classified as endangered ( vulnerable ). As the most important supplier for “African mahogany”, Khaya ivorensis is heavily exploited in its range. The regeneration in natural locations is low. Specimens do not reach their fruiting stage until 30 years after germination and there is only large seed production at three or four year intervals. Timber export bans and protective provisions exist in some countries of origin.

Taxonomy

The first description of Khaya ivorensis was made in 1909 by Auguste Chevalier in Les végétaux Utiles de l'Afrique Tropical Française , volume 5, page 207. synonyms for Khaya ivorensis A.Chev. are Khaya caudata Stapf ex Hutch. & Dalziel , Khaya klainei Pierre ex Pellegr. The specific epithet ivorensis refers to the origin Ivory Coast.

Common names

Common names are:

  • English language : African mahogany, Ivory Coast khaya, Lagos mahogany, Nigerian mahogany, Ivory Coast mahogany, Gold Coast mahogany.
  • French language : Acajou D'Afrique, Acajou.

forestry

In order to continue to fell specimens of Khaya ivorensis , new specimens must be planted, because the natural regeneration is very low in this species. It is mostly planted in closed forest stands, because on cleared or even bare areas the infestation with harmful insects is too high to achieve successfully usable specimens. Fungal attack also damages Khaya ivorensis . Planting Khaya ivorensis can improve the structure of the mixed forest.

1 kg of seeds contains 3200 to 7600 seeds. Seeds cannot be stored well. The germination rate is high at around 90%.

In addition to plantings in tropical Africa, forestry is also used in Indonesia, Malaysia and the Fiji Islands.

use

The medium-weight wood achieves a high price on the world market.

The bitter bark is used medicinally.

literature

  • Quentin Meunier, Carl Moumbogou, Jean-Louis Doucet: Les arbres utiles du Gabon. Presses Agronomiques de Gembloux, 2015, ISBN 978-2-87016-134-0 , p. 216 f, limited preview in the Google book search.
  • J. Gérard, D. Guibal, S. Paradis, J.-C. Cerre: Tropical Timber Atlas. Éditions Quæ, 2017, ISBN 978-2-7592-2798-3 , p. 54 ff, limited preview in Google Book Search.
  • HM Burkill: The useful plants of west tropical Africa , Volume 4, 1985. online at JSTOR.

Individual evidence

  1. ↑ a b c d e f g h i j k l m n o Memento from the data sheet at AgroForestryTree Database - worldagroforestrycentre.org . - PDF .
  2. ↑ Khaya ivorensis at Useful Tropical Plants.
  3. ↑ a b c Khaya ivorensis in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved September 6, 2017.
  4. ↑ a b c Khaya ivorensis in the IUCN Red List of Threatened Species 2017.1. Listed by: African Regional Workshop (Conservation & Sustainable Management of Trees, Zimbabwe, July 1996), 1998. Accessed September 6, 2017.
  5. ↑ Khaya ivorensis at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed September 6, 2017.
  6. ↑ Data sheet at Africa Museum , Prelude Medicinal Plants Database.

Web links