| # Commercial timbers |

H.G. Richter and M.J. Dallwitz

### Introduction

This database contains descriptions and an interactive identification system for hardwood taxa common in the international trade that occur in all major forest regions of the world. The package is designed primarily for use by researchers in wood and forest science, and educational facilities active in teaching wood anatomy and wood identification.

The package has been elaborated and is being maintained at the Thünen-Institute for Wood Research, Hamburg, Germany, in the form of a DELTA database (Dallwitz 1980; Dallwitz, Paine and Zurcher 1993). It was created with the intent to facilitate identification of trade timbers and information retrieval about their wood structure, for use by individuals and institutions that do not have a large institutional wood collection at their disposal.

The database contains at present the coded descriptions of close to 400 taxa (commercial timbers). The characters and accompanying character notes adhere to the IAWA List of Microscopic Features for Hardwood Identification (IAWA 1989; check with the IAWA Web site), except for some additional characters not referred to in the IAWA list. About 75% of the characters and all taxa included in the database are illustrated. The distributed version is, and will remain for some time to come, a test version, which does not claim to be ‘complete’ (it probably will never be). New taxa will be added to the database as need arises and time permits.

Identification and interrogation of the data can be conducted in five languages: English, French, German, Portuguese, and Spanish.

The interactive identification and information retrieval package uses the free program Intkey (Dallwitz, Paine and Zurcher 1995, 2000). It provides convenient and flexible access to most of the information in the DELTA database.

#### What is new in the 2015 version?

- The continuously changing botanical nomenclature has been updated.

- Around 30 additional trade timbers have been described and illustrated, especially those that are processed for imported goods from the Far East.

- Macroscopic images (cross section approximately 10x and longitudinal surfaces in natural size) available from other databases were incorporated.

- Thanks to the many indications of dedicated users of the database, spelling errors were eliminated and improvements in the coding of the characters effected.

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