Picea retroflexa

Picea retroflexa is a species in the family (Pinaceae ). It is native to China and is considered by some authors as a variety of bristle Spruce ( Picea asperata ) viewed.

Description

Picea retroflexa grows as a evergreen tree that can reach the stature heights of up to 45 meters and diameter at breast height of up to 1 meter. The gray-brown Stammborke is furrowed and irregularly divided into large, rough plates. The smooth or slightly hairy bark of the branches is initially red - or yellow-brown and turns up in the second year towards brown or brownish gray.

The resinous winter buds are conical to conical - ovoid. The slightly curved needles are linear with pointed upper end at a length of 1 to 2 centimeters and a width of 0.1 to 0.2 inches and have a square to diamond-shaped cross-section. On all sides of the needle, there are four to eight Stomatalinien.

Picea retroflexa is monoecious - getrenntgeschlechtig ( monoecious ). The flowering period extends into China from April to May The pins are oblong - elliptical shape with a length of 5-16 cm and a diameter of 2.5 to 3.5 centimeters to cylindrical. The initially green cones change color to mature in September or October through light brown to reddish brown. The seed scales rarely have zweigelappte tip, are obovate and are about 2 inches long and 1.5 inches wide. Their margins are entire, rarely slightly serrated. Elliptical, with a length of about 4 mm at a seeds have a length of about 11 mm elongated inverted - egg-shaped wing.

Distribution and location

The natural range of Picea retroflexa located in China. It includes the there located in the northern Ningxia Helan Shan, the eastern and southern Gansu, southwestern Shaanxi, western Sichuan, southeastern Xizang and Qinghai.

Picea retroflexa thrives at altitudes 2400-4700 meters. It is a species of a more continental climate Alpine climate with low annual rainfall. It grows mainly on north-facing slopes with acidic soils. At low altitudes are mainly mixed stands with the Shensi Fir ( Abies chensiensis ), the Red China birch (Betula albosinensis ), Picea aurantiaca, the Likiang spruce (Picea likiangensis ) as well as with the Chinese hemlock ( Tsuga chinensis). At higher altitudes, Picea retroflexa forms pure stands or grows along with the Schuppenrindigen Fir ( Abies squamata ).

Picea retroflexa is classified as " critically endangered " in the IUCN Red List. The stocks have shrunk in the past 50 to 70 percent. The reason mainly uncontrolled timber felling are called in the 1950s to the 1990s. The Chinese government has to protect this kind recently timber felling in western China banned among others. In addition to felling mainly make fires a risk; addition is reduced by grazing activities, the natural regeneration.

System

Picea retroflexa is within the genre of spruce (Picea ) the subgenus Picea, Picea section, the subsection Picea and serial Asperatae assigned.

The first description was in 1906 as Picea retroflexa Maxwell Tylden Masters in the Journal of the Linnean Society, Botany, Volume 37 (262 ), page 420 It is considered by some authors as a variety of bristle Spruce ( Picea asperata ).

Swell

• Christopher J. Earle: Picea retroflexa. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, retrieved on July 20, 2013 ( English).
• Liguo Fu, Nan Li, Thomas S. Elias & Robert R. Mill: Pinaceae. Picea. In: Wu Zhengyi, Peter H. Raven & Hong Deyuan (eds.): Flora of China. Cycadaceae through Fagaceae. Volume 4, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis in 1999, ISBN 0-915279-70-3, Picea asperata var asperata, p.28 ( this printed work is the same text online, Picea asperata var asperata - online).