Nauclea diderrichii Merrill (Bilinga)
Nomenclature etc. RUBIACEAE. Syn.: N. trillesii Merill, N. badi Aubrév., Sarcocephalus diderrichii De Wild. & Th. Dur., S. trillesii Pierre, S. badi Aubrév., S. xanthoxylon A. Chev. Trade and local names: Bilinga (D, G, F, NL, EGU), Opepe (WAN, GB, B), Badi, Sibo, Bedo, Ekusamba (CI), Kusia (GH), Akondok, Eke, Aloma (CAM), Bonkangu, gulu maza (ANG, ZRE), Mokese (UBA), Kilingi (EAU).
Tree. Geographic distribution: tropical Africa.
General. Heartwood basically yellow to red to brown, with streaks (orange-red). Sapwood colour distinct from heartwood colour. Basic specific gravity 0.63–0.7–0.78 g/cm³. Frequently with interlocked and ondulating grain.
Vessels. Wood diffuse-porous. Vessels arranged in diagonal and/or radial pattern or no specific pattern (often oriented diagonally), exclusively solitary. Average tangential vessel diameter 140–190–240 µm. Average number of vessels/mm² 2–5–12. Perforation plates simple. Intervessel pits restricted to overlapping vessel element tails alternate, average diameter (vertical) 5–6 µm, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Other deposits in heartwood vessels present (yellowish brown).
Tracheids and fibres. Vascular or vasicentric tracheids commonly present. Fibres of medium wall thickness. Average fibre length 1100–1650–2500 µm. Fibre pits common in both radial and tangential walls, distinctly bordered. Fibres septate and non-septate. Fibre pits conspicuously bordered and vestured.
Axial parenchyma. Axial parenchyma apotracheal and paratracheal (paratracheal parenchyma rare). Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per axial parenchyma strand (4–)6–8–10.
Rays. Rays (6–)14–18 per tangential mm, multiseriate, also if only few, 1–2–3 cells wide. Rays with multiseriate portions as wide as uniseriate portions present. Rays of one size (could also be interpreted as rays of two size classes if uniseriates are frequent). Rays composed of a single cell type and two or more cell types (uniseriates often homocellular). Homocellular ray cells square or upright. Heterocellular rays square and upright cells restricted to marginal rows. Number of marginal rows of upright or square cells more than 4. Perforated ray cells present, or absent.
Mineral inclusions. Crystals present, prismatic (crystals small in comparison with normal prismatic crystals but larger than those commonly described as crystal sand) or in form of crystal sand, located in ray cells. Crystal-containing ray cells upright and/or square or procumbent (mostly in upright cells). Silica not observed.
Miscellaneous. • Wood surface. Nauclea diderrichii. • Transverse section. Nauclea diderrichii. • Tangential section. Nauclea diderrichii. • Radial section. Nauclea diderrichii. • Fibre pits. Nauclea diderrichii. Large bordered fibre pits: radial section (left), tangential section (right). Note vestures in pit cavities (Vp). Vp». • Crystals. Nauclea diderrichii. Micro crystals occasionally in square and/or upright ray cells. • Septate fibres. Nauclea diderrichii. Fibres occasionaly septate (Fs). Fs».
Cite this publication as: H. G. Richter and M. J. Dallwitz (2000 onwards). 'Commercial timbers: descriptions, illustrations, identification, and information retrieval.' In English, French, German, and Spanish. Version: 4th May 2000. http://biodiversity.uno.edu/delta/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993 onwards, 1995 onwards, 1998) should also be cited (see General references).
