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| Commercial timbers |
Nomenclature etc. CORNACEAE (NYSSACEAE). Species included in the description: Nyssa aquatica L. (2), Nyssa ogeche Batr. (1), Nyssa sylvatica Marsh (6). Trade and local names: Nyssa aquatica: swamp tupelo, tupelo-gum, water tupelo (US); Nyssa ogeche: Ogeche tupelo, Ogeche-lime (US); Nyssa sylvatica: black tupelo, black gum, sour gum, nyssa (US). Not protected under CITES regulations.
Description based on 9 specimens. Tree. Geographic distribution: North America.
General. Growth ring boundaries distinct. Heartwood basically brown, white or grey. Sapwood colour similar to heartwood colour. Density 0.45–0.6 g/cm³.
Vessels. Wood diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows, in radial rows of 4 or more, and in clusters. Vessel outline angular. Average tangential vessel diameter 20–45–75 µm. Average number of vessels/mm² (50–)75–130(–200) (N. aquatica + N. sylvatica: 130–200, N. ogeche: 50–75). Perforation plates scalariform, with 20–30(–50) bars. 20–30 bars for N. aquatica and N. ogeche, often 50 and more bars in N. sylvatica. Intervessel pits opposite, average diameter (vertical) 4–6(–8) µm. Pit outline rectangular. Vessel-ray pits with distinct borders, different from intervessel pits, restricted to marginal rows. Helical thickenings absent.
Tracheids and fibres. Fibres very thin-walled and of medium wall thickness. Fibre pits common in both radial and tangential walls, distinctly bordered.
Axial parenchyma. Axial parenchyma present. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse and diffuse-in-aggregates. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per strand: (4–)6–10.
Rays. Rays 10–14 per tangential mm, multiseriate, 1–3 cells wide. Aggregate rays absent. 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 2–4 marginal rows of upright or square cells.
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; colour of water extract colourless to brown. Ethanol extract fluorescent. Colour of ethanol extract colourless to brown. Splinter burns to full ash. Ash bright white.
Illustrations. • Transverse section. Nyssa sylvatica. • Tangential section. Nyssa sylvatica. • Radial section. Nyssa sylvatica. • Perforation plates; intervessel pits. Nyssa sylvatica. scalariform perforation plates and opposite intervessel pitting.
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’.
