Green heart wood

Green heart
	Green heart ( Chlorocardium rodiei )
Systematics
Class :	Bedecktsamer (Magnoliopsida)
	Magnoliids
Order :	Laurels (Laurales)
Family :	Laurel family (Lauraceae)
Genre :	Chlorocardium
Type :	Green heart
Scientific name
	Chlorocardium rodiei
	( MRSchomb. ) Rohwer , HGRicht. & van der Werff

Green heartwood is a type of wood from the South American tree species Chlorocardium rodiei from the laurel family (Lauraceae). In English it is called Greenheart , other trade names are Demerara , Viruviru or Bebeere and others. a.

description

Vegetative characteristics

Chlorocardium rodiei grows as an evergreen tree and reaches stature heights of 25 to 40 meters or more. The trunk, which is up to 15, rarely 25, meters long is cylindrical and has little or no short roots or small buttress roots . The trunk diameter reaches up to 60-100 centimeters. The cinnamon-brown, relatively smooth bark is large, thin and hard.

The entire, simple and leathery leaves are opposite and ovate to lanceolate or lanceolate. They are short stalked, up to about 11-17 centimeters long, up to 4.5-7 centimeters wide and acuminate to acuminate at the tip. The veins are finely pinnate.

Generative characteristics

There are 5 centimeters wide and axillary panicles formed. The whitish, hermaphrodite, short-stalked and pleasantly scented flowers are about 5–10 millimeters in diameter. The unequal flowers are usually four-fold with a simple flower envelope . The flowers usually have 4 or / up to 8 unequal, approximately egg-shaped tepals . There may also be 12–20 stamens in 3–5 circles. The uneven, fine, fluffy, short stamens are sessile, so without stamens, and with two small glands at the base. They are shaped like a cone or tongue with counters lying one above the other. The medium-sized ovary is hairy, with short hairy pen with a small, capitate scar and he sits in a cup-shaped base of the flower .

Roundish and brownish, lightly speckled and about 5–7 centimeters large stone fruits with a persistent, woody flower base ( fruit cup ) are formed.

Systematics

The first description of Basionyms Nectandra rodiei was made in 1844 by Robert Hermann Schomburgk in London J. Bot. 3: 626. The re-allocation to the new genus Chlorocardium in 1991 by Jens Rohwer Gunter, Hans Georg Richter and Henk van der Werff in Ann. Missouri Bot. Gard. 78 (2): 388. A synonym is Ocotea rodiei (RHSchomb.) Mez . and Nectandra leucantha var. rodiaei (RHSchomb.) Griseb.

distribution

Greenheartwood is native to northeastern South America in Guyana , Suriname , Brazil , Venezuela and some islands in the Caribbean .

Wood description

The heartwood of the green heartwood can be very different in color. There are variations from yellow-green, light and dark olive or yellowish and dark brown to black. The grain of the wood is mostly straight or alternately twisted . The structure is fine and even.

The sapwood shows no clear differences from the heartwood. It has a light yellow or greenish tinge. Some wood defects can occur. This includes curvatures, core displacements, cracks, color differences and slight alternating twist. In addition, there can still be feeding holes on the sapwood.

Wood properties and uses

A former gate to the Manchester dock in the Museum of Liverpool is made of greenheart wood.

Green heartwood is a very hard, heavy and dense wood ( ironwood ), which makes it difficult to work with. It has a high resistance to bending, compression and impact , only a low degree of deformability can be seen.

Due to its special properties, Grünherzholz has a special use in bridge, port and shipbuilding . Lock gates, docks , quays and buildings are made from them, as well as sports equipment, grips for billiard sticks and fishing rods. It is used for industrial floors, shuttle boats and chemical vats.

Physical Properties
Dose density	900-1020-1100 kg / m ³
Porosity	about 32%
Shrinkage rate	radial 6.5- 8.2%
	tangential 8.1- 9.6%
	Volume 14.6-17.8%

Mechanical properties
Compressive strength	90-109-132 N / mm ³
Flexural strength	179-219-275 N / mm ³
Shear strength	12-15-19 N / mm ³
Impact strength	5.6-7.3-9.8 J / cm ²
Hardness (HBII)	72-74-76 N / mm ³
Hardness (HB)	42-49-57 N / mm ³
Modulus of elasticity	20000-21800-2700 N / mm ³
Splitting strength	radial 0.5-0.7-0.8 N / mm ³
Splitting strength	tangential 1.2-1.7-2.2 N / mm ³

processing

Due to its hardness, green heart wood is difficult to work with. Pre-drilling is required when nailing and screwing. Since the wood dulls the cutting edges of the tool, it is difficult to saw. Stellited tools should be used and a cutting speed of 15 m / s should be used. A reduced cutting angle should be used when planing.

The wood is usually easy to split and glue. It can also be polished.

Drying

The drying of green heart wood is slow.

Technical drying is only recommended after prior air drying at 40 ° C – 60 ° C.

durability

Green heartwood is very resistant to heartwood beetles and bivalve molluscs . It is fungus and insect resistant , termite and weather resistant . The wood does not accept wood preservatives .

Health risks

During machining, poisonous wood splinters can break out of the end grain . The wood dust can cause irritation of the mucous membranes and throat, headaches, shortness of breath and complaints of the digestive organs.

trade

Green heart wood is imported regularly and in small quantities in Europe. Suriname and Guyana are the main export countries. African green heart wood from Piptadeniastrum africanum and Cylicodiscus gabunensis from the legume family is used as substitute wood. Similar is still brown heart wood of Vouacapoua americana , as well as Uganda or East Africa Green Heart Warburgia ugandensis .

The timber is usually sold in square-cut blocks between 4.0 m to 8.0 m in length and a tree center diameter (BMD) of 0.2 m to 0.6 m.

literature

The CABI Encyclopedia of Forest Trees. CABI, 2013, ISBN 978-1-78064-236-9 , p. 124 f.
JG Rohwer, HG Richter, H. van der Werff: Two new genera of Neotropical Lauraceae, and critical remarks on the generic delimitation. In: Annals of the Missouri Botanical Garden. 78 (2), 1991, pp. 388-392, (online at biodiversitylibrary.org).
Terry Porter: Recognize and use wood. 2011, ISBN 978-3-86630-950-0 , p. 94.
Greenheart (PDF), from Heinrich Fahlenkamp, accessed on May 16, 2019.
R. Wagenführ: wooden atlas. 4th edition. Fachbuchverlag, 1996, ISBN 3-446-00900-0 , p. 331 ff.
Chichignoud Michaéle, Déon Gérard, Détienne Pierre, Parant Bernard, Vantomme Paul: Tropocal timber Atlas of Latin America. CIRAD-CTFT, 1990, ISBN 2-85411-012-9 , Greenheart at pp. 106-107.

Web links

Chlorocardium rodiei at Useful Tropical Plants.
Greenheart at the German Association Timber trade ( Memento from September 12, 2011 in the Internet Archive )

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Terry Porter: Recognizing and using wood. 2011, ISBN 978-3-86630-950-0 , p. 94.
↑ Chlorocardium rodiei. In: HG Richter, MJ Dallwitz: Commercial Timber. Department of Biology, University of Hamburg, 2000.
↑ online at biodiversitylibrary.org.
↑ ^a ^b ^c ^d ^e ^f ^g ^h R. Wagenführ: Holzatlas. 1996.
↑ D. Louppe, M. Brick, AA Oteng-Amoako: Plant Resources of Tropical Africa. Volume 7: Timbers 1. PROTA, 2008, ISBN 978-90-5782-209-4 , p. 180.

[Porter2011-1] ↑ ^a ^b ^c ^d ^e ^f ^g Terry Porter: Recognizing and using wood. 2011, ISBN 978-3-86630-950-0 , p. 94.

[2] Chlorocardium rodiei. In: HG Richter, MJ Dallwitz: Commercial Timber. Department of Biology, University of Hamburg, 2000.

[3] t biodiversitylibrary.org.

[Holzatlas-4] ↑ ^a ^b ^c ^d ^e ^f ^g ^h R. Wagenführ: Holzatlas. 1996.

[5] D. Louppe, M. Brick, AA Oteng-Amoako: Plant Resources of Tropical Africa. Volume 7: Timbers 1. PROTA, 2008, ISBN 978-90-5782-209-4 , p. 180.