Commercial Timbers


H. G. Richter and M. J. Dallwitz

Sacoglottis spp. (Ozouga, uchi)

Nomenclature etc. HUMIRIACEAE. Species included in the description: Endopleura uchi (Huber) Cuatrec. (syn.: Sacoglottis uchi Huber), Sacoglottis cydonioides Cuatrec., S. gabonensis (Baill.) Urban, S. guianensis Benth. Trade and local names: sAm: axuá, cumaté, uchi curuá, u. liso (BR); chanul (CO). Afr: ozouga (CM, GH); atala (NG); ugu (BJ); amwan, amouan (CI); doh, déwe (LR. Not protected under CITES regulations.

Description based on 9 specimens. Tree. Geographic distribution: tropical Africa, Mexico and Central America, and tropical South America.

General. Growth ring boundaries indistinct or absent. Heartwood basically brown, without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent.

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, exclusively solitary. Vessel outline rounded. Two distinct vessel diameter classes absent. Vessels conspicuously oval. Average tangential vessel diameter 130–175–270 µm; diameter of vessel lumina: large and very large. Average number of vessels/mm² 6–13; vessels per square millimetre few. Perforation plates scalariform, with 10–20 bars. In S. cydonioides up to 30 bars. Intervessel pits alternate, medium, not vestured. Vessel-ray pits with distinct borders or with reduced borders or apparently simple, similar to intervessel pits and different from intervessel pits, rounded or angular and horizontal to vertical, of uniform size or type and of two distinct sizes or types in the same ray cell, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels present, S. guianensis, S. gabonensis: vessels with orange to red brown deposits.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thick-walled. Fibre pits common in both radial and tangential walls, distinctly bordered. Helical thickenings absent. Fibres non-septate.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma unilateral. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 4–9. Unlignified parenchyma absent.

Rays. Rays present, 7–12 per tangential mm, multiseriate (also if only few), 1–2(–3) cells wide, narrow (2–3 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays commonly 500 to 1000 µm. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows and procumbent, square and upright cells mixed throughout the ray, mostly 2–4 marginal rows of upright or square cells and with more than 4 marginal rows of upright or square cells. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls distinct. Rays often longitudinally fused.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent.

Cambial variants. Included phloem absent.

Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent; basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown. Chrome azurol-S test negative. Froth test negative. Splinter burns to partial ash. Ash white to grey.

Illustrations. • S. gabonensis: Transverse section. Sacoglottis gabonensis. • S. gabonensis: Tangential section. Sacoglottis gabonensis. • S. gabonensis: Radial section. Sacoglottis gabonensis. • Scalariform perforation plate. Sacoglottis gabonensis. • S. guianensis: Transverse section. Sacoglottis guianensis. • S. guianensis: Tangential section. Sacoglottis guianensis. • S. guianensis: Radial section. Sacoglottis guianensis.

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: 25th June 2009.’.