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Nomenclature etc. CANNABACEAE (ULMACEAE). Incl. Celtis laevigata, C. reticulata. Trade and local names: C. occidentalis: common hackberry (US); Zürgelbaum (DE); C. laevigata: Texas sugarberry (US); C. reticulata: netleaf hackberry, western hackberry (US); palo blanco (MX). Not protected under CITES regulations.
Tree. Geographic distribution: North America, Mexico and Central America.
General. Growth ring boundaries distinct. Heartwood basically yellow, white or grey. Sapwood colour similar to heartwood colour. Density 0.52–0.63 g/cm³.
Vessels. Vessels present. Wood ring porous. Ring of earlywood vessels multiseriate. Vessels arranged in tangential bands or a diagonal and/or radial pattern, in multiples, commonly in short (2–3 vessels) radial rows (earlywood). Average tangential vessel diameter 105–230 µm (earlywood). Average vessel element length 170–290 µm. Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 7–10 µm. Vessel-ray pits with distinct borders, similar to intervessel pits. Helical thickenings present, only in narrow vessel elements, throughout the body of vessel elements. Tyloses present, thinwalled.
Tracheids and fibres. Vascular or vasicentric tracheids commonly present (vascular tracheids). Fibres of medium wall thickness. Average fibre length 900–1300 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal). Bands fine or coarse. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse-in-aggregates. Paratracheal axial parenchyma scanty (mixed with vascular tracheids). Axial parenchyma as strands. Average number of cells per strand: 2–4.
Rays. Rays 3–7 per tangential mm, multiseriate, of larger rays 4–12 cells wide. Rays of two distinct sizes, or of one size (in some specimens clearly in two sizes (1–3 seriate vs. 6–10 seriate), in others not). Height of large rays 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 to mostly 2–4 marginal rows of upright or square cells.
Mineral inclusions. Crystals occasionally present, prismatic, located in ray cells. Crystal-containing ray cells upright and/or square or procumbent. Number of crystals per cell or chamber one. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; colour of water extract colourless to brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown.
Illustrations. • Transverse section. Celtis occidentalis. • Tangential section. Celtis reticulata. C. occidentalis: large rays narrow and very high. • Radial section. Celtis reticulata. • Helical thickenings. Celtis reticulata. narrow latewood vessels with conspicuous helical thickenings.
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’.
