| | Commercial timbers |
Nomenclature etc. LECYTHIDACEAE. Trade and local names: castanha verdadeira, c. do Pará (BR); castaña del Marañon, olla de mico (CO); Brazil nut (GB); Paranuss (DE). Not protected under CITES regulations ((locally (Brazil) on the IBAMA list of endangered plants)).
Tree. Geographic distribution: tropical South America (Brasil: Acre, Amazonas, Maranhão, Pará , Rondônia).
General. Growth ring boundaries distinct or indistinct or absent. Heartwood basically pinkish to light brown; without streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.55–0.7 g/cm³. Wood of commercial potential (restricted since the trees are grown mainly for production of nuts, therefore felling is strictly regulated).
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows. Average tangential vessel diameter 120–220(–300) µm. Average number of vessels/mm² 1–4. Average vessel element length 360–620–1000 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 9–12 µm. Vessel-ray pits with distinct borders, similar to intervessel pits, of uniform size or type. Tyloses present, thinwalled. Other deposits not observed.
Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 1100–1740–2360 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal) or not marginal (or seemingly marginal). Axial parenchyma bands forming a reticulate pattern with rays. Bands fine. Apotracheal axial parenchyma diffuse-in-aggregates. Axial parenchyma as strands. Average number of cells per strand: (4–)7–8.
Rays. Rays 5–10 per tangential mm, multiseriate, 2–4 cells wide. Height of large rays up to 500 µm, or commonly 500 to 1000 µm. Rays composed of a single cell type (homocellular), or two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells or mostly 2–4 marginal rows of upright or square cells. Sheath cells absent. Tile cells absent.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells absent. Intercellular canals absent. Laticifers or tanniniferous tubes 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. Relatively small crystals in long chambered strands always located at the adaxial side of parenchyma bands. Silica not observed.
Illustrations. • Transverse section. • Tangential section. • Radial section. • Crystals. crystals in long chains, cell walls unilaterally thickened.
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: 9th April 2019. delta-intkey.com’.
