Diospyros celebica
| Diospyros celebica | ||||||||||||
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Diospyros celebica |
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| Diospyros celebica | ||||||||||||
| Bakh. |
Diospyros celebica (also called Macassar ebony , Macassar ebony , Koje itam , Gongo moitomo ) is a species of the genus Diospyros and belongs to the ebony family( Ebenaceae ). Since this species has become rare in its natural growing areas in Southeast Asia, it is now an endangered species. The wood is assigned to the group of color- striped ebony woodsand bearsthe code DSCLaccording to DIN EN 13556 .
description
Appearance and bark
The Diospyros celebica grows as an evergreen tree and reaches heights of up to 15 m and a diameter of up to 40 cm. Some rare older specimens reach considerable heights of up to 40 m. At these heights, the tree can form a branch-free trunk length of up to 20 m. The breast height diameter (BHD) of such tree specimens can be up to 100 cm or more. The bark is brownish and smooth to slightly grooved and brittle. It is peeling off in small pieces.
Leaf and flower
The simple, finely pinnate, short-stalked and eilanzettlichen or lanceolate and leathery leaves are arranged alternately and can be between 12–35 cm long and 2.5–7 cm wide. The entire leaf blade, bald on top, is fine-haired and lighter on the underside, and the tip is pointed to pointed.
The flowers are four-fold and have a double flower envelope. The female flowers appear solitary, the male in cymes . The calyx is hairy on the outside. The corolla is salver-shaped. There are 16 stamens .
The color of the round and bare berries , with a permanent calyx, differs depending on the degree of ripeness. The unripe fruits are green, the ripe ones are dark green and those that have fallen are reddish brown to dark brown. The 4–8 seeds with a length of 2–5 cm lose their ability to germinate after a few days and must be extracted from the fallen fruits. The longer the seeds are in contact with the ground, the poorer the quality of the seeds, as they would otherwise be attacked by the fungus Penicilliopsis clavariaeformis .
As a rule, this species flowers and produces fruit only once a year. It bears flowers and fruits at an age of 5–7 years.
Taxonomy
The first description of Diospyros celebica was in 1933 by Reinier Cornelis Bakhuizen van den Brink in Gardens' Bulletin. Straits Settlements 7 (2): 166.
Structural features of the wood
Macroscopically
No growth zones can be seen in the cross-section. The vessels are only visible to the human eye with the help of a magnifying glass. The colored rings can be clearly seen without a magnifying glass. In the tangential and radial section, the structure is fine, pin-cracked.
The heartwood has a brown to reddish brown basic color, which is interrupted by dark brown to black stripes. This leads to rings of different widths (3–20 mm) in different colors on the cross-section. In the radial section, these rings create a striking color stripe. In contrast to the heartwood, the sapwood is clearly separated from the core. It is pink-gray to pale red-brown in color and up to 10 cm wide. Diospyros celebica can have wood defects such as curvatures, out-of-roundness, core rot and wild growth.
Microscopic
Vessels
The vessels of Diospyros celebica are small (70-90-115 μm) and arranged individually, in pairs or in radial groups. They have a density of 4-8-12 per 1 mm² and are not very numerous in cross-section. They have a share of 10% and are often filled with black-brown core substances.
Longitudinal parenchyma
The longitudinal parenchyma is apotracheal-reticulate, partly also paratracheally. Here the proportion is around 13%. In addition to the crystal deposits, black-brown core materials are also present in the longitudinal parenchyma.
Rays
The heterogeneous wood rays are arranged irregularly and contain like the longitudinal parenchyma, crystal deposits and black-brown core matter. They have a height of 130-420-800 μm, a width of 12-19-24 μm and a density of 17-19-21 per 1 mm². The proportion of wood rays is around 20%.
Fibers
The irregular to radial fibers, of the libriform and fiber tracheid type, are straight, tangential and radially wavy. They have a length of 960-1.230-1.770 μm and, in addition to the crystal deposits, also contain black-brown core substances. The proportion of fibers is 57%.
properties
Physical and mechanical properties
| Parameter | value | unit |
|---|---|---|
| Darrdichte ( ρ dtr ): | 900-1030 | kg / m³ |
| Gross density ( ρ 12 ... 15 ): | 1100-1200 | kg / m³ |
| Gross density ( ρ green ): | 1200-1400 | kg / m³ |
| Shrinkage rate: | ||
| - radial (β r ): | about 8.2 | % |
| - tangential (β t ): | about 12.8 | % |
| Porosity : | about 32 | % |
| Parameter | value | unit |
|---|---|---|
| Tensile strength ( σ e.g. ): | k. A. | N / mm² |
| Compressive strength ( σ dB ): | 60-70 | N / mm² |
| Flexural strength (σ bB ,): | 100-120 | N / mm² |
| Shear strength (τ aB ,): | about 11 | N / mm² |
| E-module (Ε b ǁ,): | 10,100-12,400 | N / mm² |
| Transverse tensile strength : | 6th | N / mm² |
| Breaking impact work : | 38 | kJ / m² |
Chemical properties
Macassar ebony consists of pure cellulose (41%), lignin (48%) and pentosans (17%) with a pH value of 5.8. With the exception of the surface treatment and the tendency to discolouration from wood extracts, it is chemically not very reactive with a relatively high extract content. These wooden extracts change color depending on the connection. These turn brown with water and alkalis, greenish-yellow with acids and yellow with alcohol.
Occurrence and distribution
The climate is very different in the natural distribution areas of the Makassar ebony. It grows in evergreen and rain-green wet forests. This species occurs in Southeast Asia in Indonesia, Celebes ( Sulawesi ), Moluccas , Kalimantan ( Borneo ), Andamans, Philippines. According to R. Govaerts, however, it is only native to Sulawesi.
According to Schmidt and Ferguson's climate type classification, it will grow in the zones of climate types A to D, but not in types E and F. Most of the population is found at heights of 0–400 m, sometimes even at heights of up to 700 m above sea level. However, heights of 600 m above sea level do not offer optimal conditions.
Usage and editability
use
For several millennia, the Makassar ebony has found a place in the tradition of use, due to the beautiful color in combination with the almost metallic smooth surface. Long before the Indonesian government distributed the forests through the concession system, ebony was exploited to such an extent that the species Diospyros celebica is now an endangered tree species.
The Makassar ebony is one of the most valuable precious wood veneers. Because of this, it is used for the production of veneer wood and as cut wood for face veneers. It is also used in the manufacture of luxury furniture, paneling and parquet. It is also used as a special wood for turning and carving, for the back of brushes, billiard cues, buttons, musical instruments and musical instrument parts such as piano keys, fingerboards, pegs, xylophone boards, bassoons and clarinets. Only the heartwood is suitable for use. Due to the large proportion of sapwood in the trunk cross-section, the heartwood content can only be 10–20%. The Makassar ebony and all other ebony types are tasteless and odorless.
Machinability
Macassar ebony tends to crack, swell and shrink. Therefore, it should be noted that the drying process should be very gentle, as the drying process inside the wood is very slow and mild. Otherwise, especially with larger cross-sections, there is a considerable tendency to tear and burst. The wood should also be free of drafts while drying, while the frontal surface should be protected. For example, chamber drying is recommended. Despite its great hardness and brittleness, it is easy to process mechanically. Ebony woods are not very sensitive to moisture. When working with the wood, it is advisable to wear a protective mask, as the resulting wood dust irritates the mucous membranes of the eyes and the respiratory organs.
Individual evidence
- ↑ a b c d e f g h Rudi Wagenführ: Wooden atlas. Carl Hanser Verlag, 2007, ISBN 978-3-446-40649-0 , p. 233.
- ↑ a b F. Hapla: Makassar ebony (Diospyros celebica Bakh.) - a rare luxury wood from Indonesia. In: Forest Archive. Volume 71, No. 1, 2000, p. 20.
- ↑ F. Hapla: Makassar ebony (Diospyros celebica Bakh.) - a rare luxury wood from Indonesia. In: Forest Archive. Volume 71, No. 1, 2000, p. 19.
- ↑ holzwurm-page.de Hardwood species according to DIN EN 13556: 2003, accessed on January 3, 2018.
- ↑ a b c d e F. Hapla: Macassar ebony (Diospyros celebica Bakh.) - a rare luxury wood from Indonesia. In: Forest Archive. Volume 71, No. 1, 2000, p. 21.
- ↑ a b c Adam Malik: Investigations into forest measurement and forest growth fundamentals for the management of the tree species Diospyros celebica Bakh. (Ebony) in Indonesia. Cuvillier Verlag, Göttingen 2002, ISBN 3-89873-507-9 , p. 6.
- ↑ online at biodiversitylibrary.org.
- ↑ a b K. G. Dahms: The wood portrait: Ebony. Portraits of wood: Ebony. In: Wood as a raw material. Volume 48, No. 10, 1990, p. 388.
- ↑ Rudi Wagenführ: wooden atlas. Carl Hanser Verlag, 2007, ISBN 978-3-446-40649-0 , p. 234.
- ^ Rafaël Govaerts (Ed.): Diospyros celebica. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 20, 2020.
- ↑ Adam Malik: Investigations on forest measurement and forest growth fundamentals for the management of the tree species Diospyros celebica Bakh. (Ebony) in Indonesia. Cuvillier Verlag, Göttingen 2002, ISBN 3-89873-507-9 , p. 7.
- ↑ a b c d K. G. Dahms: The wood portrait: Ebony. Portraits of wood: Ebony. In: Wood as a raw material. Volume 48, No. 10, 1990, p. 388.
- ↑ Adam Malik: Investigations on forest measurement and forest growth fundamentals for the management of the tree species Diospyros celebica Bakh. (Ebony) in Indonesia. Cuvillier Verlag, Göttingen 2002, ISBN 3-89873-507-9 , p. 2.
- ↑ Ebony. In: Information service wood, leaflet series wood species. no. 84, 1988, p. 1.
- ↑ Adam Malik: Investigations on forest measurement and forest growth fundamentals for the management of the tree species Diospyros celebica Bakh. (Ebony) in Indonesia. Cuvillier Verlag, Göttingen 2002, ISBN 3-89873-507-9 , p. 10.
- ↑ KG Dahms: Asian, Oceanic and Australian Export Timbers. DRW Verlag, Leinfelden-Echterdingen 1982, p. 112.
- ↑ H. Schafflützel: lumber. Origin, characteristics, properties, use. Publishers Association of Swiss Master Carpenters and Furniture Manufacturers, Zurich (Switzerland), 1974, p. 62.
