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''Picea koyamae'' (Koyama's spruce; Japanese: ヤツガタケトウヒ ''yatsugatake-tohhi'') is a rare spruce, native to Akaishi Mountains and Yatsugatake Mountains, or Nagano and Yamanashi Prefectures in central Honshū, Japan, where it grows at 1500-2000 m altitude.〔Farjon, A. (1990). ''Pinaceae. Drawings and Descriptions of the Genera''. Koeltz Scientific Books ISBN 3-87429-298-3.〕 It is a monoecious evergreen tree growing to 25 m tall, with a trunk diameter of up to 1 m. The shoots are orange-brown, with scattered pubescence. The leaves are needle-like, 8-16 mm long, rhombic in cross-section, dark bluish-green with conspicuous stomatal lines. The cones are cylindric-conic, 4-9 cm long and 2 cm broad, maturing pale brown 5–7 months after pollination, and have stiff, smoothly rounded scales 6–18 mm long and 6-12 mm wide. Pollination takes place in late spring.〔〔Gymnosperm Database: (''Picea koyamae'' )〕 The spruce is found growing in groups of 10-20, with a total population of only about 250 mature trees. The main cause of decline is the loss of natural regeneration after typhoons, with windblown trees being replaced by the planting of other faster-growing commercially valuable species.〔〔 It is named after the Japanese botanist Mitsua Koyama. The name was first published as "koyamai", but this is an orthographical error to be corrected under the provisions of ICBN Article 60.〔Farjon, A. (1998). ''World Checklist and Bibliography of Conifers''. Royal Botanic Gardens, Kew ISBN 1-900347-54-7.〕 It is occasionally planted as an ornamental tree. The wood is similar to that of other spruces, but the species is too rare to be of economic value. ==References== Image:Picea koyamai.jpg|Recently dead specimen in the Arboretum de Chèvreloup, France File:Picea koyamae shoot.JPG|Young shoot, Arboretum in Rogów, Poland 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「Picea koyamae」の詳細全文を読む スポンサード リンク
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