''Picea koyamae'' (Koyama's spruce;

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

: ヤツガタケトウヒ or やつがたけとうひ ''yatsugatake-touhi'') is a rare

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

, endemic to the Akaishi Mountains and

Yatsugatake Mountains The are a volcanic mountain range on the border between Nagano Prefecture and Yamanashi Prefecture on the island of Honshū in Japan. Description The mountain range consists of two volcanic groups, Northern Yatsugatake Volcanic Group and S ...

in central

Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separ ...

, Japan. It is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

tree growing to tall, with a trunk diameter of up to a metre. It grows in small isolated stands in a limited area and the total area of occupation is less than . Trees that are lost to typhoons are normally replaced with other faster-growing species and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has rated the tree as " critically endangered". Some trees are in cultivation as an

ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

Description

It is a

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

tree growing to 25 m tall, with a trunk diameter of up to 1 m. The shoots are orange-brown, with scattered

pubescence Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. I ...

. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are needle-like, 8–16 mm long, rhombic in cross-section, dark bluish-green with conspicuous

stoma In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bor ...

tal lines. The

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

are cylindric-conic, 4–9 cm long and 2 cm broad, maturing pale brown 5–7 months after

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

, 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''
/ref>

Distribution

Koyama's spruce is native to the Akaishi Mountains and

, or

Nagano Nagano may refer to: Places * Nagano Prefecture, a prefecture in Japan ** Nagano (city), the capital city of the same prefecture *** Nagano 1998, the 1998 Winter Olympics *** Nagano Olympic Stadium, a baseball stadium in Nagano *** Nagano Universi ...

and Yamanashi Prefectures in central

Honshū , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, where it grows at 1500–2000 m altitude.Farjon, A. (1990). ''Pinaceae. Drawings and Descriptions of the Genera''. Koeltz Scientific Books . It 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

typhoon A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for a ...

s, with windblown trees being replaced by the planting of other faster-growing commercially valuable species. Other threats include wildfires, landslides and changes in temperature and precipitation associated with climate change. There is little genetic exchange between different fragmentary locations where it grows, and the total area of occupation by this tree is less than . The tree is named after the Japanese

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

Mitsua Koyama. The name was first published as "koyamai", but this is an orthographical error to be corrected under the provisions of

ICBN The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

Article 60.Farjon, A. (1998). ''World Checklist and Bibliography of Conifers''. Royal Botanic Gardens, Kew . It is occasionally planted as an

. The wood is similar to that of other spruces, but the species is too rare to be of economic value. Image:Picea koyamai.jpg, Recently dead specimen in the Arboretum de Chèvreloup, France File:Picea koyamae shoot.JPG, Young shoot, Arboretum in Rogów, Poland File:Picea koyamae - immatures cones.jpg, Immature cones

References

{{Taxonbar, from=Q391374 koyamae Endemic flora of Japan Trees of Japan Critically endangered flora of Asia