Pseudotsuga is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names include Douglas fir, Douglas-fir, Douglas tree, and Oregon pine. Pseudotsuga menziesii is widespread in western North America and is an important source of timber. The number of species has long been debated, but two in western North America and two to four in eastern Asia are commonly acknowledged. Nineteenth-century botanists had problems in classifying Douglas firs, due to the species' ...
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