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Nomenclature etc. MELIACEAE. Species included in the description: Azadarichta excelsa (Jack) Jacobs (2), Azadarichta indica A.H.L.Juss. (2). Trade and local names: A. indica: Niembaum, indische Stachelbeere (DE); Nim tree, Indian lilac (GB); Margosa tree, nim (IN); margosier (FR); margosa (ES); mambu, sadu (MY); A. excelsa: kelantas, limpaga, marango, ranggu, sadao tiam, saurian bawang, tiam (MY); sentang, kayu bawang; Philippine neem tree, marrango tree (GB). Not protected under CITES regulations.
Description based on 4 specimens. Tree. Geographic distribution: India, Pakistan, Sri Lanka, Myanmar (Burma), Thailand, Laos, Vietnam, Cambodia, Indomalesia.
General. Growth ring boundaries distinct (in A.indica demarcated by marginal parenchyma bands). Heartwood basically brown and red; without streaks. Sapwood colour distinct from heartwood colour. Odour distinct. Density 0.55–0.85 g/cm³. A. indica: heartwood reddish brown; A. excelsa: heartwood brown.
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows or in clusters. Average tangential vessel diameter 120–190–320 µm. Average number of vessels/mm² 3–5. Average vessel element length 120–450 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 3–5 µm, pits not vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings absent. Other deposits present (brown).
Tracheids and fibres. Fibres very thin-walled, or of medium wall thickness. Average fibre length (250–)900(–1620) µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded or not banded. Bands marginal (or seemingly marginal). Axial parenchyma bands much wider than rays. Bands coarse, 2–3 per radial mm. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty and vasicentric. Axial parenchyma as strands. Average number of cells per strand: 3–6.
Rays. Rays 4–10 per tangential mm, multiseriate, (1–)2–3(–4) cells wide. Rays with multiseriate portions as wide as uniseriate portions present and absent. Height of large rays up to 500 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, mostly 1 marginal row of upright or square cells. Homocellular rays observed only in A. excelsa.
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 axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Number of crystals per cell or chamber one. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract fluorescent (yellow); colour of water extract colourless to brown (A. excelsa), or yellow (A. indica). Ethanol extract fluorescent (A. indica: yellowish green), or not fluorescent (A. excelsa). Colour of ethanol extract colourless to brown (A. excelsa), or yellow (A. indica). Froth test positive (A. indica), or negative (A. excelsa). Splinter burns to partial ash. Ash bright white.
Illustrations. • Transverse section. Azadirachta excelsa. • Tangential section. Azadirachta excelsa. • Radial section. Azadirachta excelsa.
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’.
