Xylological review of the most cultivated species of the genus Eucalyptus L’Herit. In Argentina.

The genus Eucalyptus L’Heritier contains about 500 species ranging from dwarf shrubs to very large trees inhabiting a wide range of ecological sites. Many of the species produce timbers of commercial importance, and for this reason they have been planted in many parts of the world. In Argentina, 30 % of cultivated forest area belongs to this genus. The objective of this study is to review the anatomical features of secondary xylem in the most common species cultivated in Argentina and to update the common terminology according to the IAWA (1989) list of microscopic features for hardwood identification. We described the wood anatomical features of Eucalyptus grandis Hill. ex Maiden., Eucalyptus saligna Smith., Eucalyptus camaldulensis Dehnh., Eucalyptus globulus ssp. globulus Labill., Eucalyptus globulus ssp. maidenii F. Muell., Eucalyptus viminalis Labill., Eucalyptus dunnii Maiden. and Eucalyptus tereticornis Smith., obtaining quali-quantitative data for interspecific separation. The most useful features for differentiating between the species were heartwood colour, burning splinter test, ray height, height of the multiseriate portion of the rays, percentage of uniseriate, biseriate and triseriate rays, vessel groupings and their diagonal arrangement, axial parenchyma, rays in radial section and crystals. A key for the species differentiation is presented.

Key words: Eucalipto, wood anatomy, identification key, Argentina.