Nomenclature etc. CAESALPINACEAE. Syn.: Caesalpinia melanocarpa Griseb. Trade and local names: guajakan, yvyra vera (PY); guayacán, ibirá-verá (AR). Not protected under CITES regulations.
Description based on 3 specimens. Tree. Geographic distribution: tropical South America and temperate South America.
General. Growth ring boundaries distinct and indistinct or absent. Growth ring limits demarcated by 1–2 seriate marginal parenchyma bands. Heartwood basically brown, red, black, and purple, without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 1.195 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. Average tangential vessel diameter 28–70–140 µm; diameter of vessel lumina: medium. Average number of vessels/mm² 5–25; vessels per square millimetre few. Average vessel element length 200–250 µm. Average vessel element length short. 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 organic deposits abundant.
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thick-walled. Average fibre length 800 µm. Average fibre length short. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.
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-in-aggregates. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma lozenge. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4. Unlignified parenchyma absent.
Rays. Rays present, 7–9 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 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, 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 4–5.
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 procumbent. Crystals in procumbent ray cells not in radial alignment. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Cystoliths absent. Only few crystals in rays; in axial parenchyma considerable differences in size of cells and crystals exist between individual chains. Silica not observed.
Illustrations. • Transverse section. Caesalpinia paraguariensis (syn.: C. melanocarpa). • Tangential section. Caesalpinia paraguariensis (syn.: C. melanocarpa). • Radial section. Caesalpinia paraguariensis (syn.: C. melanocarpa).
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. http://delta-intkey.com’.