Triplochiton scleroxylon

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Triplochiton scleroxylon
Systematics
Order : Mallow-like (Malvales)
Family : Mallow family (Malvaceae)
Subfamily : Helicteroideae
Tribe : Helictereae
Genre : Triplochiton
Type : Triplochiton scleroxylon
Scientific name
Triplochiton scleroxylon
K. Schum.

The Triplochiton scleroxylon is one of two plant species of the genus Triplochiton from the family of the Malvaceae (Malvaceae). It is native to Africa. Abachi is, for example, the common trade name for wood in German-speaking countries ; Trade names for the wood are, for example, Samba , Obeche , African whitewood or Ayous .

description

Appearance and leaf

7th Green Week in Berlin, 1932. Abachi tribe from Nigeria, weight 6.3 tons.

Triplochiton scleroxylon is a fast-growing, evergreen or mostly deciduous large tree . It usually reaches heights of 45, sometimes 50 meters and trunk diameters of usually around 1.5 meters. The unusually straight and cylindrical, often angular trunk in older specimens is usually free of branches up to a height of up to 30 meters and has strong buttress roots that reach up to a trunk height of about 8 meters. The ash-gray or yellowish-brown, 7 to 30 mm thick bark is initially smooth and later scaly and cracked; it often has vertical lines of lenticels . Young trees have a cylindrical crown and are leafed almost to the base. Later the trees have a high, dense, spherical crown with not widely spreading branches, which ends flat at the top in old trees.

The alternate leaves arranged on the branches are rarely stalked 1.5 to usually 3 to 10 cm long. The simple leaf blade is 10 to 20 cm long and wide, lobed to split, with five to seven leaf lobes with an arrow-shaped and a five- to seven-veined blade base; they are often larger and deeper split on young trees. The egg-shaped, triangular or elongated and entire leaf lobes have a rounded, blunt to pointed upper end. The leaf surfaces initially have brown star hairs, but soon become bald. The 2 to 4 cm long stipules fall off early and leave a ring-shaped leaf trail.

Inflorescence and flower

The main flowering time is in the dry season. Trees do not develop the first flowers until they are 15 to 20 years old. The axillary or terminal, dichotomously branched, paniculate zymous inflorescence is 4 to 10 cm long with a densely hairy inflorescence axis. The 3 to 5 mm long bracts and bracts are ephemeral early. The 4 to 5 mm long flower stalks are hairy golden tomentose in the herbarium.

The cup-shaped, hermaphrodite and short-stalked flowers are radially symmetrical and five-fold with a double flower envelope . The flower stalks sit on a "joint". The sepals, which are triangular at a length of about 7 mm, are fused up to a third of their length and have brown star hairs. The roof-tile arranged, densely silky hairy, white and at their base red-purple-colored, spreading petals are with a length and width of about 1 cm wide-inverted-egg to heart-shaped. The 30 to 46 equally long stamens are fused in pairs at their base. The carpels are surrounded by five petal-like staminodes . There are five free, approximate, and upper carpels. The five styluses are fused. The short and hairy androgynophore is 3 to 3.5 mm long. It is cross-pollination necessary.

fruit

The split fruit , which is brown to reddish-brown when ripe, breaks down into one to five partial fruits ( wing nuts ) that look like individual maple fruits. The simply winged, more or less intense, softly hairy partial fruits are more or less rhombic with a length of about 2 cm and a width of about 1 cm. The wings are elongated-egg-shaped with a thickened edge with a length of 4 to 6 cm and a width of 1.2 to 2 cm.

The number of chromosomes is 2n = 40.

Abachi veneer

Systematics

The first description of the genus Triplochiton and the species Triplochiton scleroxylon was made in 1900 by Karl Moritz Schumann in Botanical Yearbooks for Systematics, Plant History and Plant Geography , 28, p. 330. The type protolog is " Cameroon: Yaunde-Station, at 800 m - ZENKER u. STAUDT n. 595 - Buds in December 1894 - ZENKER n. 298 - Blooming in March 1890 ”, these herbarium specimens were deposited in the herbarium in Berlin. It has been suggested that it is a Sterculia species. Schumann found that the deviations from Sterculia are so great that he set up the new genus Triplochiton and even wanted to set up a new family Triplochitonaceae.

The generic name Triplochiton is derived from the Greek words triplostichus for three rows and - chiton for to cover. The specific epithet scleroxylon is derived from the Greek words sclero - for hard and xylon for wood.

Wood

Description of the wood

The heartwood is white to light yellow and sharply demarcated from the up to 15 cm thick sapwood . Freshly felled, damp wood has an unpleasant odor that disappears when it dries. The light wood is easy to work with. Sawdust can cause allergies. The wood is not durable because it is attacked by termites, beetles and fungi.

Use of the wood

The solid wood is used, for example, for strips, profiled wood , models and prostheses . It is used for lightweight components in bodywork and sauna construction, for picture frames and for packaging. It is also made as a veneer .

In the 1970s, Abachi was also used in organ building to make wooden pipes. However, after it became known that Abachi is mostly obtained through overexploitation, a process of rethinking began, in the course of which more traditional native wood species, such as B. oak, beech, maple, pine and spruce were used.

Occurrence

Triplochiton scleroxylon is found in the tropical evergreen and semi-evergreen rainforest south of the Sahel from Senegal to Angola . Main occurrences are in tropical West Africa in the Ivory Coast (called "Samba" there), Ghana ("Wawa"), Nigeria ("Obeche") and Cameroon ("Ayous"), the Central African Republic , Sierra Leone , the Democratic Republic of the Congo and of the Republic of the Congo .

ecology

The German Federal Agency for Nature Conservation (BfN) advises against the use of this wood. According to a report published in 2007, the extraction of abachi from the Central African basin is mainly carried out through planned exploitation and the removal of the most valuable trees. Through the roads laid out by the loggers, poachers also penetrate the previously untouched forests and hunt wild animals. a. Monkeys and antelopes are on the verge of extinction. In contrast to some other jungle woods, Abachi is not available as FSC-certified.

According to Greenpeace , the use of Abachi is to be seen as particularly critical, as it is not available with an environmental certificate and it is most likely the result of the destruction of primeval forests and overexploitation .

literature

Web links

Individual evidence

  1. ↑ a b c d e f g h i j k Timbers 1, Volume 7 by D. Louppe, AA Oteng-Amoako & M. Brink (eds.): Plant resources of tropical Africa.
  2. ^ A b R. RB Leakey: Physiological approaches to the conservation and improvement of Triplochiton scleroxylon - a West African timber tree. In: FT Last, AS Gardiner: Forest and woodland ecology: an account of research being done in ITE. Cambridge, NERC / Institute of Terrestrial Ecology, 1981, pp. 105-109. (ITE Symposium, 8): PDF .
  3. ↑ a b c d e First publication at biodiversitylibrary.org.
  4. ↑ Triplochiton scleroxylon at Tropicos.org. Missouri Botanical Garden, St. Louis.
  5. ↑ Abachi - data sheet at holzhandel.de.
  6. ↑ Triplochiton scleroxylon in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  7. ↑ Protection of Forests - Bearing National Responsibility and Acting Globally - page 29 (PDF; 1.86 MB) at the Federal Agency for Nature Conservation.
  8. ↑ Beate Steffens Tropical Timbers and Climate Protection at Greenpeace, January 24, 2008.
  9. ↑ Wood guide - Good woods, bad woods (PDF; 333 kB) at Greenpeace.