OKALA (Xylopia aethiopica)
Trade Name
Okala
Scientific Name
Xylopia aethiopica A.Rich.
Family
ANNONACEAE
Common Names
Okala (Gabon); Ogana (Gabon); N'kana (Congo); Livomo (Congo); Kana (Congo); Akui (Cameroon)
Scientific Name Synonyms
Xylopicrum aethiopicum (Dunkley) Kuntze; Xylopia gilletii De Wild.; Xylopia eminii Engl.; Xylopia dekeyzeriana De Wild.; Uvaria aethiopica (Dunkley) A. Rich.; Unona aethiopica Dunal; Habzelia aethiopica (Dunkley) De Candolle
Description Of The Tree
Botanical Description
The tree reaches a height of 23 to 40 m. The bole is clear and straight with a maximum length of 30 m. The trunk diameter attains 70 to 130 cm.
Natural Habitat
Xylopia aethiopica occurs in fringing forests, coastal thickets, in swamp forests and in dense, evergreen stands.
Wood Identification
Anatomic Description Of Wood
Wood diffuse porous. Occasionally vessels exclusively solitary (over 90%). Tangential diameter of vessel lumina 150 to 200 micras (medium). Non-vestured pits. Vessels per mm2 less than 6 (rare). Simple perforation plates. Vessel-ray pits similar to intervessel Axial parenchyma in continuous tangential lines or fine bands. Non-crystals in axial parenchyma cells. 3 to 4 cells per parenchyma strand. Axial parenchyma in narrow bands on lines up to 3 cells wide. Axial parenchyma bands over 4 per mm. 4 to 10 rays per mm (medium). Rays non-storied. Rays 1 to 4 seriate. Homogeneous rays and/or sub-homogeneous rays (all ray cells procumbent). Non-septate fibers. Fibers with simple to minutely bordered pits.
Availability
Cites Status
Unrestricted
General Wood Description
Color
The heartwood is white or pale brown with a regular stripe appearance on the radial face, it is not clearly demarcated.
Grain
Straight; grain has no particular influence on drying, machining and finishing qualities.
Texture
Texture is usually medium to coarse.
Luster
The wood luster is reported to be rather low.
Natural Durability
Not durable; important risks of decay attacks at any processing step, from logs up to final products. It must receive preservative treatment. Sensible to termites attack. The heartwood is sensible to Lyctus attacks.
Natural durability index (1= Very high durability, 7=Vey low durability)
5
Resistance To Impregnation
Difficult to treat with only a low penetration of the preservative products.
Wood Physical Properties
Basic Density or Specific Gravity (O.D. weight/vol. green) (g/cm³)
0.58
Air-dry Density (Weight and volume at 12%MC) (g/cm³)
0.64
Total shrinkage Tangential (Saturated to 0%MC) (%)
7.9
Total shrinkage Radial (Saturated to 0%MC) (%)
4.5
Dimensional stability ratio (Total Tangential Shrinkage %/Total Radial Shrinkage %)
1.8
Wood Chemical Properties
Wood Mechanical Properties
Bending Strength (MOR),12%MC (kgf/cm²)
1194
Stiffness (MOE) 12%MC (kgf/cm²)
193192
Compression parallel to fiber 12%MC (kgf/cm²)
608
Compression perpendicular to fiber 12%MC (kgf/cm²)
81
Shear strength radial 12%MC (kgf/cm²)
60
Janka hardness (side) 12%MC (kgf)
506
Janka hardness (end grain) 12%MC (kgf)
609
Workability
Sawing
It is easy to saw.
Rotary Veneer Cutting
Suitable for slicing, also suitable for peeling if treated.
Sliced Veneer
Suitable for slicing, also suitable for peeling if treated.
Machining
Machining of this species is reportedly easy.
Planing
Moderately easy; tools must be cautiously sharpened.
Moulding
Moderately easy; tools must be cautiously sharpened.
Turning
30
Boring
Moderately easy; tools must be cautiously sharpened.
Mortising
Moderately easy; tools must be cautiously sharpened.
Nailing
No particular problem.
Gluing
Glues well if basic gluing technical rules are followed.
Sanding
Easy to perform; it gives good results.
Polishing
Needs pre-coating.
Response To Hand Tools
No particular problems.
REFERENCED USES
End Uses Summary
HOUSING GENERAL, beams, joists, boards, flooring, parquet, frames, steps, FURNITURE AND CABINETS, common furniture, PLYWOOD AND VENEER, faces, cores, common veneer, TURNING, ornaments, OTHER AND MUSICAL INSTRUMENTS, handicrafts
General Housing
- 10 - Silica in Timbers
Beams
- 11 - Prospect: The wood database
Joists
- 12 - Tropical timbers of the world. Part I-Tropical American Species
Boards
- 13 - Dry kiln schedules for commercial woods. Temperate and tropical. Section III. Latin American (Mexico, Central, and South America) Woods–Conventional Temperatures
Flooring
- 14 - Handbook of Hardwoods
Parquet
- 15 - Empire Timbers
Frames
- 16 - Woods of the World
Steps
- 17 - Tree Conservation Database
Furniture Cabinets
- 21 - Tropical timbers of the world. Part III-Southeast Asian and Oceanian Species.
Furniture, Common
- 23 - Handbook of Hardwoods
Panels, Veneers
- 25 - Directory of Timber Trade Malaysia
Faces
- 26 - Annual Review and Assessment of the World Timber Situation 1998-ITTO
Cores
- 27 - Embassy of Brazil in Japan
Common Veneer
- 29 - Embassy of Ecuador in Japan
Turning
- 30 - Embassy of Honduras in Japan
Ornaments
- 31 - Embassy of Colombia in Japan
Handcraft
- 66 - Maderas latinoamericanas. VII. Caracteristicas anatomicas. propiedades fisicomecanicas, de secado, y tratabilidad de la madera juvenil de Cordia alliodora (Ruiz & Pav. Oken.)
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