Commercial Timbers


H. G. Richter and M. J. Dallwitz

Luehea divaricata Mart. (Ka'a oveti)

Nomenclature etc. TILIACEAE. Trade and local names: kaá oveti (PY); ivitinga, caoueti, pau-de-canga, estribeira, pau-de-estribo, ibatingui (BR); ibatinuí, sota caballo, caibotí, azota caballo, Francisco Alvarez, árbol de San Francisco (AR); asoita (UY). Not protected under CITES regulations.

Description based on 9 specimens. Tree. Geographic distribution: southern Brazil and temperate South America.

General. Growth ring boundaries distinct. Growth ring limits demarcated by marginal parenchyma bands. Heartwood basically brown and red, without streaks. Odour indistinct or absent. Density 0.6–0.7 g/cm³.

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. Multiples with up to 5 vessels. Average tangential vessel diameter 40–90–150 µm; diameter of vessel lumina: medium. Average number of vessels/mm² 10–20; vessels per square millimetre few. Average vessel element length 250–350 µm. Average vessel element length short. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 6–8 µm, small to medium, not 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, brown organic contents.

Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled. Average fibre length 600–900 µm. Average fibre length short. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate. Fibre pits frequent in radial walls, often in two rows.

Axial parenchyma. Axial parenchyma present, banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide. Axial parenchyma apotracheal and paratracheal. 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(–5). Unlignified parenchyma absent.

Rays. Rays present, 10–14 per tangential mm, multiseriate (also if only few), 1–5 cells wide, narrow (2–3 seriate) and 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 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 present. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent. In some specimens rays in two different sizes, uni- and multisertiates.

Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular (horizontal or straight). Number of ray tiers per axial millimetre 2–3. Low rays (uniseriates and multiseriates) storied, the large rays not.

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 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 in radial alignment and not in radial alignment. Crystal-containing axial parenchyma cells not chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Silica not observed.

Illustrations. • Transverse section. Luehea divaricata. • Tangential section. Luehea divaricata. • Radial section. Luehea divaricata. • Miscellaneous. Luehea divaricata. Note tile cells (TC) and solitary crystals (CR) in rays. TC. CR.

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.’.