Commercial Timbers


H. G. Richter and M. J. Dallwitz

Leucaena spp. (Guaje, ipil-ipil)

Nomenclature etc. FABACEAE-MIMOSOIDEAE. L. leucocephala (Lam.) De Wit; L. collinsii Britton & Rose; L. esculenta (DC.) Benth.; L. diversifolia (Schltdl.) Benth.; L. lanceolata S. Watson; L. magnifica (C.E. Hughes) C.E. Hughes; L. matudae (Zarate) C.E. Hughes; L. multicaptulata Schery; L. pulverulenta (Schltdl.) Benth.; L. salvadorensis Standl. ex Britton & Rose; L. shannonii Donn. Sm.; L. trichandra (Zucc.) Urb.; L. trichodes (Jacq.) Benth. Trade and local names: ipil-ipil (PH); huaxin, uaxim (MX); koa haole (US-Hawaii); jumbie bean, horse tamarind, leadtree (US); white babool, nagurjun, nattu cavundal, kaniti (IN); 'Leucaena' (trade). Not protected under CITES regulations.

Tree. Geographic distribution: India, Pakistan, Sri Lanka to Indomalesia (cult.), or North America to tropical South America.

General. Growth ring boundaries distinct. Heartwood basically brown, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.6–0.8(–0.9) g/cm³. Wood of commercial potential.

Vessels. Vessels present. Wood semi-ring-porous to 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 100–200(–250) µm; diameter of vessel lumina: large to very large. Average number of vessels/mm² 5–10; vessels per square millimetre few. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 7–10 µm, medium, vestured. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels present (light to dark brown).

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres of medium wall thickness to very thick-walled. Average fibre length 840–1000–1150 µm. Average fibre length short to medium. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres septate and non-septate and non-septate. Septate fibres evenly distributed.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Marginal bands often discontinuous, conspicuous only through concentration of prismatic crystals. Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma lozenge. Axial parenchyma fusiform and as strands. Average number of cells per axial parenchyma strand 3–5. Unlignified parenchyma absent.

Rays. Rays present, 4–7 per tangential mm, multiseriate (also if only few), 2–4(–5) cells wide, narrow (2–3 seriate) to of medium width (3–5 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.

Storied structures. Storied structure present or absent, rays not storied, axial parenchyma storied (only in some specimens, difficult to detect).

Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes absent.

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

Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered and not chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Crystals almost exclusively in cells of marginal bands and single (diffuse) strands. Silica not observed.

Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (weakly greenish-blue); basically colourless to brown or shade of brown. Heartwood extractives not leachable by water. Ethanol extract not fluorescent. Colour of ethanol extract red or shade of red. Froth test negative. Splinter burns to full ash. Ash white to grey to bright white.

Illustrations. • Transverse section. Leucaena glauca. • Tangential section. Leucaena glauca. • Radial section. Leucaena glauca.

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.’.