Dalbergia cearensis
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Wood sample of Dalbergia cearensis from the collection of the Institute for Wood Research of the Johann Heinrich von Thünen Institute in Hamburg-Lohbrügge |
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Dalbergia cearensis (also called royal wood, violet wood or violet wood, Brazilian jacaranda-violeta, miolo-de-negro, pau-violeta, violeta) is a species of the Dalbergia genus( Dalbergia ) within the legume family (Fabaceae). Like all other Dalbergia species,this endangered species hasbeen on the CITES listsince the end of 2016.
description
Appearance and bark
Dalbergia cearensis grows as a tree that reaches heights of up to about 15 meters with a breast height diameter (BHD) of 0.4 meters. The trunk remains free of knots up to a height of 8 meters. The bark of Dalbergia cearensis is coarse-scaly and light brown to brown.
leaf
The alternately arranged and stalked leaves are pinnate unpaired. The petiole is 3–4 inches long. On the 6–8 centimeter long leaf rhachis , the short-stalked leaflets are arranged opposite in up to six pairs. The pointed to pointed leaflets are entire and ovate to oblong or obovate, they are 4–6 centimeters long and 2.5-4 centimeters wide. The plant sheds its leaves at the beginning of the dry season, new leaves sprout at the beginning of the rainy season, the foliage phase lasts about four to six months.
Generative characteristics
The fragrant flowers sit in compact, terminal or axillary and paniculate inflorescences. The petals of the flower are pale yellow in color. The flag of the typical butterfly flower is not indented in the middle. The calyx is unevenly toothed. A single flower is around 4.5 millimeters long. The species blooms and produces fruit at the beginning of the rainy season.
The ripe dark brownish wing nuts are pointed to pointed at the end and are solitary, their length ranges from 30.61 to 47.57 mm, the width from 7.83 to 10.88 mm, the thickness from 2.94 to 4.95 mm. Their weight is between 100 and 177 milligrams. The flat, smooth seed is slightly kidney-shaped.
The seeds do not have any dormancy; in 70%, germination begins three days after the fruit has been deposited. These are usually scattered around the mother tree, up to a few meters away, by the wind.
Wood
According to DIN EN 13556 , the wood of Dalbergia cearensis has the abbreviation DLCR. The sapwood is clearly separated in color from the heartwood . The sapwood is white to gray-yellow, the width varies greatly. The heartwood, on the other hand, is light brown to dark brown-violet and very varied, finely striped black to black-violet, which leads to a beautiful look.
The natural coloring is not permanent because UV light and oxygen bleach the wood surface. The result is a less attractive shade of brown. Even surface treatment can only slow down this process, but not stop it.
The smell of freshly cut wood is aromatic to slightly sweet. The scent disappears when dry. The structure is predominantly straight-grained, partly wavy and slightly twisted . The longitudinal section appears clearly pin-cracked. Growth zones , on the other hand, are barely visible.
Tangential cut
Cross-section and radial section
Radial and cross-section
bark
Macroscopically
The vessels or pores of Dalbergia cearensis are small to medium-sized (20-70-150 μm), few to numerous and irregularly distributed. They are semi-ring-pored to scattered-pored.
Microscopic
The wood rays can only be seen under a magnifying glass. There the fine and storied structure can be seen. Thylles are not present.
- Microscope images
Microscopic radial section of Dalbergia cearensis (50 nm)
Microscopic radial section of Dalbergia cearensis (200 nm)
Microscoped polarized radial section (visibility of the crystals) (100 nm)
Microscopic tangential section of Dalbergia cearensis (100 nm)
Microscopic cross section of Dalbergia cearensis (200 nm)
Microscopic cross section of Dalbergia cearensis (500 nm)
Microscopic cross section of Dalbergia cearensis (200 nm; unstained)
properties
The wood of Dalbergia cearensis is heavy, slightly shrinking and has very good stamina. It is also very hard, has a high density and, due to its low elasticity, can only be worked well with increased effort and furthermore tends to tear, splinter and / or even break. Due to the oily wooden surface and the high density, gluing work is rather problematic. The wood is easy to turn and polish.
The heartwood is weatherproof and resistant to fungal attack.
As with all other rosewood trees , Dalbergia cearensis is characterized by the frequent crookedness , out-of-round growth and throatiness.
physical values
The values below include all Dalbergia species. The range of variation of individual species is smaller. Unfortunately, little is known about other mechanical values.
| Parameter | value | unit |
|---|---|---|
| density | ||
| - undried ( round wood ): | 1,000-1,300 | kg / m³ |
| - lean dry : | 800-1,000 | kg / m³ |
| Compressive strength ( air dry ): | 60-80 | N / mm² |
| Flexural strength (air dry): | 110-150 | N / mm² |
use
The royal wood was used for fine interior work, veneers and inlays until it was included on the CITES list. However, due to the small dimensions, massive furniture was not made from it. The wood was also used to build instruments such as B. high quality recorders are used.
history
The wood from, for example, Dalbergia cearensis and related species, including other genera, has been one of the most sought-after tropical imported woods since the 18th century because of its special color. A particularly large increase in the use of D. cearensis occurred in the second half of the 19th century after the invention of sliced veneer . Due to the rare distribution and the relatively small-sized trunks, the price for these types of wood was always very high and their use was limited.
In the course of time, misleading wood names emerged, as the woods belonging to the genus Dalbergia grow in regions that are far apart from one another and with different languages. As rosewood or Jacaranda nowadays refers to all kinds of related genera Dalbergia and Machaerium . The similarities relate to the dark, streaked heartwood and medium to coarse pores. A distinction is difficult, however, since these types of wood , which belong to the legume family, have largely similar properties and hardly differ in terms of the wood pattern.
Origin of name
Since Dalbergia cearensis with the French kings Louis XIV. And Louis XV. When furnishing and furniture wood was very popular, it bears the common name of king wood.
Occurrence and location
The species is endemic to Brazil, older information for Mexico does not refer to this species. It grows in the northeast of the country, from Ceará (from which the name is derived) and southern Piauí to southern Bahia . Occurrences in the north of Minas Gerais appear possible according to the location requirements, but have not yet been proven. It grows in the open dry forest, called Caatinga in Brazil , mostly in better, deeper and more densely wooded locations, for example at the foot of hills.
literature
- Harri Lorenzi: Árvores Brasileiras. Vol. 3, Instituto Plantarum, 2009, 2011, ISBN 978-85-86714-33-7 , p. 140. ( online at StuDocu).
Individual evidence
- ↑ a b c d e Hans Schafflützel: Timber : origin, characteristics, properties, use. 2nd Edition. Association of Swiss Master Carpenters and Furniture Manufacturers , Zurich 1974, ISBN 3-85891-001-5 , p. 57.
- ^ A b c André M. de Carvalho: A Synopsis of the Genus Dalbergia (Fabaceae: Dalbergieae) in Brazil. In: Brittonia. Volume 49, No. 1, 1997, pp. 87-109, JSTOR 2807701 .
- ↑ a b c d e Delta Intkey. Retrieved November 23, 2016 .
- ↑ CNIP. Retrieved December 27, 2016 .
- ^ Rubens Plantas do Brasil. Retrieved December 27, 2016 .
- ↑ Francisco Carlos Barboza Nogueira, Alípio Jose de Sousa Pacheco Filho, Maria Izabel Gallão, Antonio Marcos Esmeraldo Bezerra, Sebastião Medeiros Filho: Fenologia de Dalbergia cearensis Ducke (Fabaceae) em um fragmento de floresta estacional, no semiárido do Nordeste, Brasil. In: Revista Árvore. Volume 37, No. 4, 2013, doi: 10.1590 / S0100-67622013000400009 .
- ↑ Francisco Carlos Barboza Nogueira, Sebastião Medeiros Filho, Maria Izabel Gallão: Caracterização da germinação e morfologia de frutos, sementes e plântulas de Dalbergia cearensis Ducke (pau-violeta) - Fabaceae. In: Acta Botanica Brasilica. Volume 24, No. 4, 2010, doi: 10.1590 / S0102-33062010000400013 .
- ↑ a b Francisco Carlos Barboza Nogueira, Sebastião Medeiros Filho, Raquel Negrão Baldoni, Talita Ariela Sampaio e Silva: Is the Seed Dispersal Related to Spatial Pattern of Individuals in Populations? The case of Dalbergia cearensis. In: American Journal of Plant Sciences. Volume 5, No. 2, 2014, Article ID 50158, doi: 10.4236 / ajps.2014.520316 .
- ↑ a b c d e f Hans Georg Richter: Wood as a raw material for making musical instruments. Moeck Verlag, 1988, ISBN 3-87549-035-5 , p. 29.
- ↑ a b c d Unknown author: Information service wood: Leaflet series wood types. Sheet 53, Verein Deutscher Holzeinfuhrhäuser eV and Arbeitsgemeinschaft Holz eV, 1979.
- ↑ a b c Klaus-Günther Dahms: Wood as raw and material: The wood portrait - rosewood. Springer-Verlag, 1989, pp. 337-342.
- ↑ a b Wood Database. Retrieved December 2, 2016 .