• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.1-17
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• 2000

Crystals in the woods and barks of Populus maximowiczii and Populus nigra ${\times}$ maximowiczii were examined by light microscopy, scanning electron microscopy and soft X-ray. Populus examined had the wetwood and the heartwood of Populus showed higher moisture content than in adjacent sapwood. The crystals can be detected clearly by the soft X-ray due to their higher densities than the wood. Crystals in xylem wood of Populus were found mainly at heartwood. However, they were concentrated in specific areas such as in color-stained area or along the specific annual rings. Crystals showed the highest occurrence around the pith. Within a growth ring the amount of crystals in earlywood was more abundant than in latewood. Crystals were observed mainly at vessels and fibers although they occurred at all kinds of cells in heartwood. Crystals in the bark were scattered evenly both in inner bark and in outer bark. Populus nigra${\times}$maximowiczii showed higher frequency of leaf knots than Populus maximowiczii.