Жалған шырша туқымдасы: Сипаттамасы мен түрлері

Genus of conifers in the family Pinaceae

Pseudotsuga ,/sj//uː//d//oʊ/'/t//s//uː//ɡ//ə/ is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names for species in the genus include Douglas fir, Douglas fir, Douglas tree, Oregon pine and Bigcone spruce. Pseudotsuga menziesii (Douglas fir proper) 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' similarity to various other conifers better known at the time; they have at times been classified in Pinus, Picea, Abies, Tsuga, and even Sequoia. Because of their distinctive cones, Douglas firs were finally placed in the new genus Pseudotsuga (meaning "false hemlock") by the French botanist Carrière in 1867. The genus name has also been hyphenated as Pseudo tsuga.

The tree takes its English name from David Douglas, the Scottish botanist who first introduced Pseudotsuga menziesii into cultivation at Scone Palace in 1827. Douglas is known for introducing many native American tree species to Europe. The hyphenated form "Douglas fir" is used by some to indicate that Pseudotsuga species are not true firs, which belong to the genus Abies.

By far the best known is the very widespread and abundant North American species Pseudotsuga menziesii, a taxonomically complex species divided into two major varieties (treated as distinct species or subspecies by some botanists): coast Douglas fir or "green Douglas fir", on the Pacific coast; and Rocky Mountain Douglas fir or "interior Douglas fir", in the interior west of the continent. According to some botanists, Rocky Mountain Douglas fir extends south into Mexico to include all Mexican Douglas fir populations, whereas others have proposed multiple separate species in Mexico and multiple varieties in the United States. Morphological and genetic evidence suggest that Mexican Douglas fir should probably be considered a distinct variety within P. menziesii. All of the other species are of restricted range and little known outside of their respective native environments, where they are often rare and of scattered occurrence in mixed forests; all those have unfavorable conservation status. The taxonomy of the Asian Douglas firs continues to be disputed, but the most recent taxonomic treatment accepts four species: three Chinese and one Japanese. or broken down into additional species and varieties. In the current treatment, the Chinese species P. sinensis is further subdivided into two varieties: var. sinensis and var. wilsoniana.

Douglas firs are used as food plants by the larvae of some Lepidoptera species, including autumnal moth, bordered white, engrailed moth, pine beauty and turnip moth. The gelechiids Chionodes abella and Chionodes periculella and the tortrix moth Cydia illutana have been specifically recorded on P. menziesii.

A California Native American myth explains that each three ended bract is the tail and two tiny legs of a mouse that hid inside the scales of the tree's cones during forest fires, and the tree was kind enough to be its enduring sanctuary. A Douglas fir species, Pseudotsuga menziesii, is the state tree of Oregon.