Nomenclature etc. ULMACEAE. + Celtis laevigata, C. reticulata. Trade and local names: C. occidentalis: hackberry, common hackberry, sugarberry (US); Zürgelbaum (DE); C. laevigata: sugarberry, hackberry, Texas sugarberry (US); C. reticulata: netleaf hackberry, hackberry, western hackberry (US); palo blanco (MX). Not protected under CITES regulations.
Tree. Geographic distribution: North America to Mexico and Central America.
General. Growth ring boundaries distinct. Heartwood basically white or grey, without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent. Density 0.52–0.63 g/cm³.
Vessels. Vessels present. Wood ring-porous. Vessels arranged in tangential bands or diagonal and/or radial pattern, in multiples, commonly 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, not vestured. 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 in vessels present, thinwalled.
Tracheids and fibres. Vascular or vasicentric tracheids commonly present (vascular tracheids). Fibres very thin-walled, or of medium wall thickness. Average fibre length 900–1300 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Axial parenchyma bands marginal (or seemingly marginal), fine, up to three cells wide or coarse, more than three cells wide. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty (mixed with vascular tracheids). Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4.
Rays. Rays 3–7 per tangential mm, multiseriate (also if only few), 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.
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. Other cambial variants absent.
Mineral inclusions. Crystals present (occasionally), prismatic, located in ray cells. Crystal-containing ray cells upright and/or square or procumbent, upright and/or square ray cells not chambered. Crystals in procumbent ray cells not in radial alignment. Number of crystals per cell or chamber one. Crystal containing cells of normal size. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; basically colourless to brown or shade of brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown.
Illustrations. • Transverse section. Celtis occidentalis. • Tangential section. Celtis reticulata. Note: Large rays narrow and very high in C. occidentalis. • Radial section. Celtis reticulata. • Helical thickenings in latewood vessels. Celtis reticulata. Note: 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: 25th June 2009. http://delta-intkey.com’.