Entandrophragma utile
| Entandrophragma utile | ||||||||||||
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Tribe of Entandrophragma utile with epiphytes ( Platycerium angolense and Platycerium stemaria ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Entandrophragma utile | ||||||||||||
| Dawe & Sprague (Sprague) |
Entandrophragma utile is a species ofthe mahogany family (Meliaceae). It is common in tropical Africa. The trade abbreviation according to DIN EN 13556 for this tree species is ENUT and is known in the trade under the names Sipo (mahogany) , Utile and Assié .
description
Habit and leaf
Entandrophragma utile grows as a deciduous tree and reaches heights of 55 to 65 meters and trunk diameters of up to 2 to 3 meters. The trunk is mostly straight and cylindrical, with buttress roots 3 to 5 meters high, which sometimes lengthen into long flat roots . The trunk is free of knots up to a height of 40 meters. The cracked bark with elongated scales is silver-gray to brown or yellowish-brown. The inner bark is pink-red, fibrous and without a pronounced odor. The treetop is dome-like with some thick branches. The initially short-haired, quickly balding bark of the young twigs is brownish and has leaf scars .
The alternate leaves are arranged at the ends of the branches and are divided into a petiole and a leaf blade. The petiole is 5-15 inches long and has two weak lateral ribs or is slightly winged at the base. The leaf blade is pinnate in pairs and the 12 to 32 pinnate leaves are arranged opposite to alternate. The sheet rhachis is up to 45 centimeters long and slightly grooved. The stalk of the leaflets is 1–5 millimeters long. The paper-like to thin leathery leaflets are elongated-elliptical to elongated-lanceolate or elongated-ovoid with a length of rarely 3 to mostly 5 to 15.5 centimeters and a width of rarely 1.5 to usually 2 to 5.5 centimeters to slightly heart-shaped and asymmetrical base and mostly short-pointed upper end. The leaflets are almost bare, but have tufts of hair in the corners of the leaf veins . There is pinnate nerve with 10 to 16 lateral nerves on each side of the median nerve. There are no stipules .
Inflorescence, flower and fruit
Entandrophragma utile is dioeciously segregated ( diocesan ). The inflorescence is a short-haired axillary or terminal flower of up to 25 centimeters in length in the form of a panicle . It is a simple, unisexual flower. The flower stalk is 2–3 millimeters long. The calyx is cup-shaped, short lobed, 0.5–1 millimeters long and hairy on the outside. The petals are exposed and egg-shaped. They are 5–6 millimeters long, have short hairs on the outside and are greenish-white in color. The stamens merge into an urn-shaped tube 3–4 millimeters long and are fused with ten anthers at the slightly toothed or almost entire tip. There is a constant top, conical, fünfzelliger ovary before. The scar is disc-shaped. Furthermore, the male flowers have rudimentary ovaries. The female flowers have small, non-opening anthers.
The fruit is a pendulous, club-shaped capsule of 14–28 cm × 4.5–7 cm. It is brown-black in color and has numerous red-brown lenticels . It opens from the top with five woody fruit flaps. The up to 30 seeds are attached in the middle. The seeds are, including the wings, 8-11 centimeters long and medium to dark brown in color. The seedlings germinate above ground, with the cotyledons often remaining in the seed coat. The hypocotyl is around 4-8.5 inches long. The epicotyl is 2 to 4 centimeters long. The first two leaves are simple and opposite.
Wood
The heartwood is reddish brown after drying, wherein the sapwood settles color distinct from the heartwood. There is a pronounced alternating twist . The (core) wood has durability class 2–3 (according to EN 350-2.1994) and is therefore considered to be durable against wood-destroying organisms (fungi, insects, termites, etc.).
Structural features
Since the wood in the early and late wood has trachea , it is considered to have scattered pores. The average pore diameter is 230 µm and is relatively large compared to other tree species. The rays are narrow and mostly less than 1 millimeter high. The growth limits are marked by narrow marginal parenchyma bands. Other manifestations of the axial parenchyma are short, wavy ribbons between the marginal ligaments.
use
The wood can be used and installed indoors as well as outdoors. It is particularly suitable for frame construction (windows, house doors, winter gardens), floors (parquet, floorboards), stairs, furniture and wall and ceiling coverings. Since the wood hardly warps after it has been built, it is often used for construction purposes and less and less for decorative purposes.
Machinability
Sipo is considered to be excellently machinable, but due to the alternating twist and the associated fiber deviation it can lead to cracks, flaking or tears in some types of processing. Therefore, the wood must be dried particularly gently.
| Parameter | value | unit |
|---|---|---|
| Bulk density | 0.59 | g / cm 3 |
| Compressive strength | 58 | N / mm 2 |
| modulus of elasticity | 11000 | N / mm 2 |
| Flexural strength | 100 | N / mm 2 |
| tensile strenght | 110 | N / mm 2 |
Hazard and protection
The species Entandrophragma utile is not yet listed as endangered by CITES. However, since the wood is in great demand on the wood market due to its good properties, the natural stocks are steadily dwindling.
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Individual evidence
- ↑ a b c d D. B. Mujuni: Entandrophragma utile (Dawe & Sprague) Sprague. (No longer available online.) In: PROTA (Plant Resources of Tropical Africa / Ressources végétales de l'Afrique tropicale), Wageningen, Netherlands. D. Louppe, AA Oteng-Amoako, M. Brink, 2008, archived from the original on February 1, 2014 ; accessed on January 21, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Printed version with the same wording: DB Mujuni: Timbers 1 . PROTA Foundation, Wageningen 2008, ISBN 978-90-5782-209-4 , p. 245-249 .
- ↑ a b c d Gerald Koch: Determination and properties of timber.
- ↑ CITES
Web links
- Entandrophragma utile inthe IUCN Red List of Threatened Species 2013.2. Listed by: W. Hawthorne, 1998. Retrieved May 5, 2014.
- Sipo leaflet ( Memento from November 15, 2016 in the Internet Archive ).
- In the wood species database on de.trotec.com, accessed on November 15, 2016.