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''Actinostrobus'' is a genus of coniferous trees in the Cupressaceae (cypress family). Common names include cypress, sandplain-cypress and cypress-pine, the last of these shared by the closely related genus ''Callitris''. There are three species in the genus, all endemic to southwestern Western Australia: *''Actinostrobus acuminatus'' - Dwarf cypress, Creeping pine, Moore cypress pine〔Eckenwalder, J.E. 2009. ''Conifers of the World: The Complete Reference''. Timber Press.〕 *''Actinostrobus arenarius'' - Sandplain-cypress〔 *''Actinostrobus pyramidalis'' - Swan river cypress, Swamp cypress, Western Australian swamp cypress, King George's cypress pine〔 A 2010 study of ''Actinostrobus'' and ''Callitris'' has placed all three species of ''Actinostrobus'' within an expanded ''Callitris'' based on analysis of 42 morphological and anatomical characters. 〔 Piggin, J., and Bruhl, J.J. (2010). () Phylogeny reconstruction of ''Callitris'' Vent. (Cupressaceae) and its allies leads to inclusion of ''Actinostrobus'' within ''Callitris''. ''Australian Systematic Botany'' 23: 69-93. 〕 They are shrubs or small trees, reaching tall. The leaves are evergreen, of two forms; juvenile needle-like leaves long on young seedlings (but occasional into adulthood in ''A. acuminatus''), and scale-like adult leaves, long with only the apex free. The leaves are arranged in six rows along the twigs, in alternating whorls of three. The male cones are small, long, and are located at the tips of the twigs. The female cones start out similarly inconspicuous, maturing in eighteen to twenty months to long and wide, globular to acute-ovoid, with six thick, woody scales, arranged in two whorls of three, and a further nine to fifteen thin, sterile basal scales. The cones remain closed on the trees for many years, opening only after being scorched by a bushfire; this then releases the seeds to grow on the newly cleared burnt ground. The closest relative of ''Actinostrobus'' is ''Callitris'', which is much more widespread, occurring in most of Australia, and differs in its cones lacking the basal whorls of small sterile scales. The wood of ''Actinostrobus'' is light, soft and aromatic, but the plants are too small for any significant use. They are occasionally planted as ornamental shrubs, but their use is restricted by the high risks imposed by their very high flammability in bushfires. ==References== 〔 * *Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4. *(Gymnosperm Database - ''Actinostrobus'' ) *(Arboretum de Villardebelle - Photos of cones ) 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「Actinostrobus」の詳細全文を読む スポンサード リンク
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