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''Eucalyptus regnans'', known variously as mountain ash, swamp gum, or stringy gum, is a species of ''Eucalyptus'' native to Tasmania and Victoria in southeastern Australia and the tallest flowering plant and one of the tallest trees in the world, second to the coast redwood (''Sequoia sempervirens''). A straight-trunked tree with smooth grey bark and a stocking of rough brown bark to above the ground, it regularly grows to , with the tallest living specimen, the Centurion, standing tall in Tasmania. The white flowers appear in autumn. Victorian botanist Ferdinand von Mueller described the species in 1871. ''Eucalyptus regnans'' grows in pure stands in tall wet forest, sometimes with rainforest understory, in temperate areas receiving over rainfall a year on deep loam soils. many of these have been logged, including trees of a greater height than trees of any species now living—one specimen recorded at over in Victoria. Killed by bushfire, ''Eucalyptus regnans'' regenerates from seed and has a lifespan of several hundred years. Mature ''Eucalyptus regnans''-dominated forests have been found to store more carbon than any other forest known. Known in the timber industry as Tasmanian oak, ''E. regnans'' is logged for its wood and grown in plantations in New Zealand and Chile as well as Australia. ==Taxonomy== Victorian Botanist Ferdinand von Mueller described ''Eucalyptus regnans'' in 1871, using the Latin ''regnans'' "ruling" as its species epithet. He noted, "This species or variety, which might be called Eucalyptus regnans, represents the loftiest tree in British Territory." However, until 1882 he considered the tree to be a variety of ''Eucalyptus amygdalina'' and called it thus,〔 not using the binomial name ''Eucalyptus regnans'' until the ''Systematic Census of Australian Plants'' in 1882, and giving it a formal diagnosis in 1888 in Volume 1 of the ''Key to the System of Victorian Plants'', where he describes it as "stupendously tall". Von Mueller did not designate a type specimen, nor did he use the name ''Eucalyptus regnans'' on his many collections of "White Mountain Ash" at the Melbourne Herbarium. Victorian botanist Jim Willis selected a lectotype in 1967, one of the more complete collections of a specimen from the Dandenong Ranges, that von Mueller had noted was one "of the tall trees measured by Mr D. Boyle in March 1867." Genetic testing across its range of chloroplast DNA by Paul Nevill and colleagues yielded 41 haplotypes, divided broadly into Victorian and Tasmanian groups, but also showing distinct profiles for some areas such as East Gippsland, northeastern and southeastern Tasmania, suggesting the species had persisted in these areas during the Last Glacial Maximum and recolonised others. There was some sharing of haplotype between populations of the Otway Ranges and northwestern Tasmania, suggesting this was the most likely area for gene flow between the mainland and Tasmania in the past. ''Eucalyptus regnans'' is widely known as the mountain ash, due to the resemblance of its wood to that of the northern hemisphere ash (''Fraxinus''). Swamp gum is a name given to it in Tasmania, and stringy gum in northern Tasmania.〔 Other common names include white mountain ash, giant ash, stringy gum, swamp gum and Tasmanian oak.〔 Von Mueller called it the "Giant gum-tree" and "Spurious blackbutt" in his 1888 ''Key to the System of Victorian Plants''.〔 The timber has been known as "Tasmanian oak", since early settlers likened the strength of its wood that of English oak (''Quercus robur'').〔 The brown barrel (''Eucalyptus fastigata'') is a close relative, the two sharing the rare trait of paired inflorescences arising from axillary buds. Botanist Ian Brooker classified the two in the series ''Regnantes''.〔 The latter species differs in having brown fibrous bark all the way up its trunk, and was long classified as a subspecies of ''E. regnans''.〔 The series lies in the section ''Eucalyptus'' of the subgenus ''Eucalyptus'' within the genus ''Eucalyptus''.〔 Hybridisation with messmate (''Eucalyptus obliqua'') is not uncommon and has been recorded from several sites in Victoria and Tasmania.〔 Hybrids with red stringybark (''Eucalyptus macrorhyncha'') occur in the Cathedral Range in Victoria. These trees resemble ''E. regnans'' in appearance though lack the paired inflorescences. They have the oil composition of ''E. macrorhyncha''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Eucalyptus regnans」の詳細全文を読む スポンサード リンク
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