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Nomenclature etc. FABACEAE-CAESALPINIOIDEAE. Oxystigma oxyphyllum (Harms) J. Léonard (syn.: Pterygopodium oxyphyllum Harms), O. buchholzii Harms, O. gilbertii J. Léonard, O. mannii (Oliv.) Harms. Trade and local names: tchitola, kitola (CG); lolagbola (NG); emola, m'babou (GA); tschibudimbu, akwakwa (CD); tola chinfuta (AO). Not protected under CITES regulations.
Description based on 12 specimens. Tree. Geographic distribution: tropical Africa.
General. Growth ring boundaries indistinct or absent. Heartwood basically brown to red; with streaks to without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.55–0.65 g/cm³. Wood often very resinous with dark exudations.
Vessels. Vessels present. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 150–250 µm. Average number of vessels/mm² 2–4. Average vessel element length 130–300 µm. Wood with rather large, diffusely distributed resin canals which cannot be distinguished from vessels macroscopically (number of vessels/mm² up to 10 including resin canals). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 4–6 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses absent. Other deposits present, brown gum deposits quite frequent.
Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness. Average fibre length 900–1600(–1900) µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded or not banded. Bands marginal (or seemingly marginal). Bands fine to coarse. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric, or aliform, or confluent. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 6–8 per tangential mm, multiseriate, (1–)2–4(–5) cells wide. Height of large rays up to 500 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells to mostly 2–4 marginal rows of upright or square cells. Rays occasionally also homocelular.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals present, non-traumatic origin, oriented axially, axial intercellular canals diffusely arranged. Resin canals often as large as vessels and therefore not distinct macroscopically.
Mineral inclusions. Crystals present or not observed, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystals very few and in some specimens absent. Silica not observed.
Illustrations. • Transverse section. Oxystigma oxyphyllum. axial intercellular canals (IC), diffuse. IC --»». IC --»». IC --»». • Tangential section. Oxystigma oxyphyllum. • Radial section. Oxystigma oxyphyllum. • Intercellular canal. Oxystigma oxyphyllum. vessel (V) with cellwall and axial intercellular canal (IC) with traces of epithelial cells. V. IC.
The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.
Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 9th April 2019. delta-intkey.com’.
