Commercial Timbers


H. G. Richter and M. J. Dallwitz

Nectandra megapotamica (Sprengel) Mez (Laurel negro)

Nomenclature etc. LAURACEAE. Syn.: Tetranthera megapotamica Sprengel, Nectandra saligna Nees, Oreodaphne tweediei Meissner var. cymulosa Meissner, Nectandra saligna Nees var.obscura Meissner, Nectandra racemifera Meissner, Nectandra tweediei (Meissner) Mez, Nectandra briquetii Hassl.,Nectandra membranacea Hassl., Nectandra membranacea Hassl. var.saligna (Nees) Hassl., N. membranacea Hassl. var. saligna (Nees) Hassl. forma floribunda Hassl. Trade and local names: laurel hu (PY); canela preta, c. imbuia, c. fedorenta (BR); ayuí-hú, laurel negro, laurel hú, laurel canela, laurel amarillo, canela negra, laurel, ayuy morotí, a. pará, laurel ayuy, l. blanco, l. overo (AR). Not protected under CITES regulations.

Description based on 5 specimens. Tree. Geographic distribution: southern Brazil to temperate South America.

General. Growth ring boundaries distinct. Latewood with thicker-walled and radially flattened fibres. Heartwood basically brown, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.52–0.68 g/cm³. Green wood with very unpleasant odour which disappears when the wood is dried but becomes noticable again upon rehumidification (Tortorelli, 1956).

Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Vessel outline rounded. Two distinct vessel diameter classes absent. Average tangential vessel diameter (80–)125–150 µm; diameter of vessel lumina: large. Average number of vessels/mm² (6–)9–12; vessels per square millimetre few. Average vessel element length 200–700 µm. Average vessel element length medium. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–13 µm, large, not vestured. Vessel-ray pits with reduced borders or apparently simple, rounded or angular or horizontal to vertical, of two distinct sizes or types in the same ray cell, located throughout the ray. Helical thickenings absent. Tyloses in vessels present, thinwalled.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled, or of medium wall thickness. Average fibre length 950 µm. Average fibre length medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres exclusively septate. Septate fibres evenly distributed. Fibres with (2-)3–6 septae.

Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma vasicentric and confluent. Axial parenchyma as strands. Average number of cells per axial parenchyma strand (2–)3–6(–8). Unlignified parenchyma absent.

Rays. Rays present, 8–9 per tangential mm, multiseriate (also if only few), 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, mostly 1 marginal row of upright or square cells. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure absent.

Secretory structures. Oil and mucilage cells present, associated with axial parenchyma, ray parenchyma, and fibres. Secretory cells contain mostly mucilage. Intercellular canals absent.

Cambial variants. Included phloem absent. Other cambial variants absent.

Mineral inclusions. Crystals present, needle-like (acicular), styloids or elongate, and in form of crystal sand, located in ray cells and axial parenchyma cells. Crystal-containing ray cells upright and/or square and procumbent, upright and/or square ray cells not chambered. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber more than one. Crystals in one cell or chamber of the same size and of two distinct sizes. Crystal containing cells of normal size. Cystoliths absent. Some crystalline blocks in fibre lumina. Silica not observed.

Illustrations. • Transverse section. Nectandra megapotamica. • Tangential section. Nectandra megapotamica. • Radial section. Nectandra megapotamica.

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.’.