Difference between revisions of "Microberlinia brazzavillensis (PROTA)"

Latest revision as of 19:09, 2 August 2015

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber
Fuel
Fibre
Conservation status

Microberlinia brazzavillensis A.Chev.

Protologue: Rev. Int. Bot. Appl. Agric. Trop. 26: 588 (1946).

Family: Caesalpiniaceae (Leguminosae - Caesalpinioideae)

Vernacular names

• African zebrawood, zingana, zebrano (En).
• Zingana, zebrano (Fr).

Origin and geographic distribution

Microberlinia brazzavillensis occurs in Gabon and Congo.

Uses

The wood, traded as ‘zingana’ and ‘zebrano’, is mainly used for decorative furniture, turnery, sliced veneer and faces of plywood. It is also used for flooring and musical instruments such as guitars and drums, and it has been used for ski manufacture. It is suitable for construction, joinery, interior trim, mine props, ship building, vehicle bodies, railway sleepers, ladders, sporting goods, toys, novelties, tool handles and pulpwood. In Gabon it is used as firewood.

In traditional medicine in Congo the pounded leaves are rubbed on the body for the treatment of rheumatism and oedema of the legs.

Production and international trade

In the 1960s Gabon exported on average 230 m³/year of ‘zingana’ sawn wood. According to ATIBT statistics, Gabon exported 2000 m³ of zingana logs in 2001, 9000 m³ in 2002, 6000 m³ in 2003, 7500 m³ in 2004, 11,800 m³ in 2005, 11,500 m³ in 2008 and 15,000 m³ in 2009. Cameroon exported 1500 m³ of sawn wood in 2006, but this probably refers to Microberlinia bisulcata A.Chev., which is also traded as ‘zingana’.

Properties

The heartwood is pale yellowish brown with narrow darker brown streaks, taking a golden brown and lustrous tinge upon exposure, and distinctly demarcated from the up to 10 cm wide, whitish sapwood. The grain is usually wavy or interlocked, texture coarse but even. The wood is lustrous. The striped pattern gives quarter-sawn surfaces a very decorative appearance. Fresh wood has an unpleasant odour, which disappears after drying.

The wood is medium-weight to heavy, with a density of 690–880 kg/m³ at 12% moisture content, and hard. It must be dried slowly and stacked with care; there is a serious risk of distortion. To minimize degrade during drying, quarter-sawing is recommended. The shrinkage rates are high, from green to oven dry 4.8–9.6% radial and 7.3–12.3% tangential. Once dry, the wood is moderately stable in service.

At 12% moisture content, the modulus of rupture is 72–147(–198) N/mm², modulus of elasticity 16,200–17,500 N/mm², compression parallel to grain 51–77 N/mm², shear 7.5–12.5 N/mm², cleavage 13–26 N/mm and Chalais-Meudon side hardness 4.1–6.1.

The wood saws fairly easily, but cross-cutting may give rough surfaces. A smooth surface may be difficult to obtain in planing due to the presence of interlocked grain; sanding gives a good finish. In most operations the wood has moderate blunting effects on tools. It tends to split upon nailing, making pre-boring necessary. The gluing properties are good, and the wood polishes and varnishes well. It slices well but veneer must be handled carefully to prevent cracking.

The heartwood is durable. It is moderately resistant to termite and fungal attacks, but is resistant to dry-wood borers. The sapwood is susceptible to Lyctus attacks. The heartwood is extremely resistant to impregnation with preservatives, making incising necessary, but the sapwood is permeable. Induction of asthma by exposure to the saw dust has been recorded.

Adulterations and substitutes

The wood is quite similar in appearance to that of Julbernardia pellegriniana Troupin.

Description

Medium-sized to large tree up to 45 m tall; bole branchless for up to 15 m, straight and cylindrical, up to 150 cm in diameter, usually with rather low buttresses; bark surface scaly, reddish, inner bark fibrous, pink; crown dense; twigs short-hairy. Leaves alternate, paripinnately compound with 7–14 pairs of leaflets; stipules free, oblong-linear, c. 1 cm long, caducous; petiole and rachis together 6–7 cm long, grooved, more or less winged, slightly hairy but becoming glabrous; leaflets opposite, sessile, oblong, 10–16 mm × 5–7 mm, base truncate, asymmetrical, apex rounded or slightly notched, glabrous, pinnately veined. Inflorescence a terminal panicle, reddish hairy. Flowers bisexual, zygomorphic, 5-merous; pedicel 1–5.5 mm long, at apex with 2 ovate, thickened, hairy bracteoles 7.5–10 mm long; sepals unequal, 5–7 mm × 1–3 mm, 2 fused and 3 free, glabrous; petals free, oblong-spatulate, 6–7 mm × 2–3 mm, 1 slightly broader than other 4, clawed, nearly glabrous, usually white; stamens 10, 9 fused at base but 1 free, 9–11 mm long; ovary superior, with long stipe, style long and slender. Fruit an oblong pod up to 18 cm × 5 cm, flattened, with distinct stipe at base, pointed at apex, with prominent longitudinal ridge, glabrous, dehiscent with 2 woody valves, 3–6-seeded. Seeds elliptical, c. 2 cm × 1.5 cm, flattened, black. Seedling with epigeal germination; hypocotyl 3–8.5 cm long, epicotyl 3–6.5 cm long; first 2 leaves opposite, with 8–11 pairs of leaflets.

Other botanical information

Microberlinia comprises 2 species and is restricted to Central Africa.

Microberlinia bisulcata

Microberlinia bisulcata A.Chev. is a medium-sized to large tree to 45 m tall, with a cylindrical bole branchless for up to 20 m and up to 75 cm in diameter, probably endemic to Cameroon. Its wood is traded under the same trade names as that of Microberlinia brazzavillensis and has similar uses and properties; it has a density of 700–850 kg/m³ at 12% moisture content. Microberlinia bisulcata is classified as critically endangered in the IUCN Red List, because clearance for agriculture has resulted in large-scale habitat decline, and exploitation has caused population declines.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

• Growth rings: 2: growth ring boundaries indistinct or absent.
• Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; 23: shape of alternate pits polygonal; 25: intervessel pits small (4–7 μm); 26: intervessel pits medium (7–10 μm); 29: vestured pits; 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 43: mean tangential diameter of vessel lumina ≥ 200 μm; 46: ≤ 5 vessels per square millimetre; (47: 5–20 vessels per square millimetre); (58: gums and other deposits in heartwood vessels).
• Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 66: non-septate fibres present; 69: fibres thin- to thick-walled; 70: fibres very thick-walled.
• Axial parenchyma: 80: axial parenchyma aliform; 81: axial parenchyma lozenge-aliform; 82: axial parenchyma winged-aliform; 83: axial parenchyma confluent; 85: axial parenchyma bands more than three cells wide; 89: axial parenchyma in marginal or in seemingly marginal bands; 91: two cells per parenchyma strand; 92: four (3–4) cells per parenchyma strand.
• Rays: 96: rays exclusively uniseriate; 97: ray width 1–3 cells; 104: all ray cells procumbent; (106: body ray cells procumbent with one row of upright and/or square marginal cells); 115: 4–12 rays per mm; 116: ≥ 12 rays per mm.
• Storied structure: (122: rays and/or axial elements irregularly storied).
• Secretory elements and cambial variants: (131: intercellular canals of traumatic origin).
• Mineral inclusions: (136: prismatic crystals present); (142: prismatic crystals in chambered axial parenchyma cells); (143: prismatic crystals in fibres).

(S. N’Danikou, P.E. Gasson & E.A. Wheeler)

Growth and development

Flowering and fruiting is at the end of the rainy season.

Ecology

Microberlinia brazzavillensis occurs in savanna areas, forest margins, along rivers, and on lagoon sides on sandy soil, usually as isolated trees or in small stands, but sometimes in nearly pure stands.

Harvesting

In Gabon the minimum bole diameter allowed for harvesting is 70 cm.

Handling after harvest

The sapwood is often removed from logs before export.

Genetic resources

Microberlinia brazzavillensis is classified as vulnerable in the IUCN Red List, because populations are often small and trees often scattered, with less than 1 tree per km².

Prospects

The wood of Microberlinia brazzavillensis is very decorative because of its striped appearance, but it is quite difficult to work. It enters the international market, but as it has only a limited distribution and is considered vulnerable, care should be taken that it is only exploited in a sustainable way.

Major references

• ATIBT (Association Technique Internationale des Bois Tropicaux), 1986. Tropical timber atlas: Part 1 – Africa. ATIBT, Paris, France. 208 pp.

• Aubréville, A., 1968. Légumineuses - Caesalpinioidées (Leguminosae - Caesalpinioideae). Flore du Gabon. Volume 15. Muséum National d’Histoire Naturelle, Paris, France. 362 pp.

• Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.

• Chudnoff, M., 1980. Tropical timbers of the world. USDA Forest Service, Agricultural Handbook No 607, Washington D.C., United States. 826 pp.

• de Saint-Aubin, G., 1963. La forêt du Gabon. Publication No 21 du Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 208 pp.

• Sallenave, P., 1955. Propriétés physiques et mécaniques des bois tropicaux de l’Union française. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 129 pp.

• Sallenave, P., 1971. Propriétés physiques et mécaniques des bois tropicaux. Deuxième supplément. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 128 pp.

• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan. 248 pp.

• Wieringa, J.J., 1999. Monopetalanthus exit: a systematic study of Aphanocalyx, Bikinia, Icuria, Michelsonia and Tetraberlinia (Leguminosae, Caesalpinioideae). Wageningen Agricultural University Papers 99(4). Wageningen Agricultural University, Wageningen, Netherlands. 320 pp.

• World Conservation Monitoring Centre, 1998. Microberlinia brazzavillensis. In: IUCN 2010. Red list of threatened species. Version 2011.2. [Internet] http://www.iucnredlist.org. March 2012.

Other references

• Allen, O.N. & Allen, E.K., 1981. The Leguminosae: a source book of characteristics, uses and nodulation. MacMillan, London, United Kingdom. 812 pp.

• Anonymous, 1966. Neue Importholzkunde, Teil I Afrika (107): zebrano (Microberlinia brazzavillensis + M. bisulcata, Familie der Leguminosen, Unterfamilie der Caesalpiniaceen, syn. Brachystegia fleuryana). Holz-Zentralblatt 92(123): 2191.

• ATIBT (Association Technique Internationale des Bois Tropicaux), 2005. Statistics. ATIBT Newsletter 22: 26–47.

• ATIBT (Association Technique Internationale des Bois Tropicaux), 2007. Statistiques. La lettre de l’ATIBT 26: 38–52.

• Aubréville, A., 1970. Légumineuses - Césalpinioidées (Leguminosae - Caesalpinioideae). Flore du Cameroun. Volume 9. Muséum National d’Histoire Naturelle, Paris, France. 339 pp.

• Bâ, M., Plenchette, C., Duponnois, R., Moyersoen, B. & Diédhiou, A.G., 2012. Ectomycorrhizal symbiosis of tropical African trees. Mycorrhiza 22: 1–29.

• Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.

• Bush, R.K., Yunginger, J.W. & Reed, C.E., 1978. Asthma due to African zebrawood (Microberlinia) dust. The American review of Respiratory Disease 117(3): 601–603.

• Cheek, M. & Cable, S., 2000. Microberlinia bisulcata. In: IUCN 2010. Red list of threatened species. Version 2011.2. [Internet] http://www.iucnredlist.org. March 2012.

• CIRAD Forestry Department, 2009. Zingana. [Internet] Tropix 7. http://tropix.cirad.fr/ africa/ zingana.pdf. March 2012.

• CTFT (Centre Technique Forestier Tropical), 1949. Zingana. Fiche botanique et forestière. Bois et Forêts des Tropiques 9: 71–74.

• Keay, R.W.J., Hoyle, A.C. & Duvigneaud, P., 1958. Caesalpiniaceae. In: Keay, R.W.J. (Editor). Flora of West Tropical Africa. Volume 1, part 2. 2nd Edition. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 439–484.

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

• Normand, D. & Paquis, J., 1976. Manuel d’identification des bois commerciaux. Tome 2. Afrique guinéo-congolaise. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 335 pp.

• Phongphaew, P., 2003. The commercial woods of Africa. Linden Publishing, Fresno, California, United States. 206 pp.

• Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp.

• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.

Sources of illustration

• Aubréville, A., 1968. Légumineuses - Caesalpinioidées (Leguminosae - Caesalpinioideae). Flore du Gabon. Volume 15. Muséum National d’Histoire Naturelle, Paris, France. 362 pp.

• de Saint-Aubin, G., 1963. La forêt du Gabon. Publication No 21 du Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 208 pp.

Author(s)

• M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Brink, M., 2012. Microberlinia brazzavillensis A.Chev. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 3 April 2025.

• See the Prota4U database.