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H. G. Richter and M. J. Dallwitz

Ulmus spp. (Ulme, Rüster, elm)

Nomenclature etc. ULMACEAE. Ulmus campestris (L.) Spach. (Syn.: Ulmus carpinifolia Gled., Ulmus campestris Sm. var. vulgaris Planch.); Ulmus americana L. (Syn.: Ulmus americana var. americana). Trade and local names: U. campestris: Ulme, Rüster (DE); Dutch elm (GB, US); Europees iepen (NL); orme champetre (FR); olmo campestre (IT); olmo comune; (ES) jilm polni; (CZ) wiaz (PL); ulm de camp (RO); mezei szil (HU); harunire (JP). U. americana: white elm, American elm (US, CA), orme d'Amérique (FR). Not protected under CITES regulations.

Tree. Geographic distribution: U. campestris Europe, excl. Mediterranean, Mediterranean incl. N. Africa and Middle East, and temperate Asia, or North America (U. americana).

General. Growth ring boundaries distinct. Heartwood basically brown to red to white or grey, with streaks. Sapwood colour distinct from heartwood colour. Density 0.44–0.64–0.82 g/cm³.

Vessels. Vessels present. Wood ring-porous. Ring of earlywood vessels uniseriate or multiseriate. Vessels arranged in tangential bands or diagonal and/or radial pattern (wavy), in multiples, commonly short (2–3 vessels) radial rows and in clusters (latewood). Average tangential vessel diameter 150–210–260 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 in vessels present, thinwalled.

Tracheids and fibres. Fibres of medium wall thickness. Average fibre length 900–1200–2400 µm. Fibre pits mainly restricted to radial walls, simple to minutely bordered.

Axial parenchyma. Axial parenchyma not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty to vasicentric. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 2–4.

Rays. Rays 5–7 per tangential mm, multiseriate (also if only few), (1–)4–7 cells wide. Height of large rays commonly 500 to 1000 µm. Rays composed of a single cell type (homocellular); homocellular ray cells procumbent.

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.

Illustrations. • Macro images. Ulmus carpinifolia. Transverse. Radial. • Transverse section. Ulmus rubra.. • Tangential section. Ulmus rubra.. • Radial section. Ulmus rubra..


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’.

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