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Nomenclature etc. FABACEAE-MIMOSOIDEAE. Syn.: Prosopis algarrobilla Griseb. var. nigra Griseb. Trade and local names: algarrobo dulce, a. morado, a. negro (AR); a. amarillo (UY). Not protected under CITES regulations.
Description based on 2 specimens. Tree. Geographic distribution: temperate South America.
General. Growth ring boundaries distinct or indistinct or absent. If distinct, demarcated by discontinuous marginal parenchyma bands composed of smaller and mostly crystalliferous cells; macroscopically quite distinct. Heartwood basically light to dark brown; with streaks. Sapwood colour distinct from heartwood colour. Odour indistinct or absent. Density 0.75–0.83–0.87 g/cm³.
Vessels. Vessels present. Wood semi ring porous or diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Tyloses absent. Other deposits present, abundant amber coloured deposits in vessels.
Tracheids and fibres. Fibres of medium wall thickness to very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma present, banded. Bands marginal (or seemingly marginal). Axial parenchyma bands much wider than rays. Bands coarse. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse, or diffuse-in-aggregates. Paratracheal axial parenchyma vasicentric, aliform, and confluent. Aliform parenchyma of the lozenge type. Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays multiseriate, 2–5 cells wide. Height of large rays commonly 500 to 1000 µm. Rays composed of a single cell type (homocellular) and two or more cell types (heterocellular); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows (heterocellular rays only sporadically), mostly 1 marginal row of upright or square cells.
Storied structures. Storied structure absent.
Secretory structures. Intercellular canals absent. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem 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. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Compound crystals (twins) in procumbent and square ray cells; size of crystals and crystalliferous cells very variable. Silica not observed.
Physical and chemical tests. Froth test negative.
Illustrations. • Transverse section. • Tangential section. • Radial section.
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’.
