Ostryopsis

Ostryopsis is a plant genus in the birch family ( Betulaceae ). The three species of the genus are found only in China.

• 3.1 Notes and references

Description

Appearance and leaves

Ostryopsis species are deciduous shrubs. The alternate arranged on the branches leaves are stalked. The simple leaf blade is usually irregular and doubly serrate or incised.

Inflorescences, flowers and fruits

Ostryopsis species are monoecious getrenntgeschlechtig ( monoecious ). The male inflorescences are lateral or terminal, short -stalked, ährig - zymöse, cylindrical catkins, which are protected in winter from buds. You have many overlapping bracts, about each being assisted by a bloom, but no cover pages ( Brakteolen ). The male flowers contain four to eight stamens and, as with wind-pollinated taxa often, no bracts are present. The dust bags are made of two fused counters. The female inflorescences are lateral or terminal and racemose - shaped little head. They contain a bundle of a number of flowers and have support leathery leaves form a tube with the upper end of in each case two lobed flower. In the female flowers calyx leaves are present, which are adherent to the ovary.

The ovoid - spherical nutlets have raised ribs, are wingless and completely surrounded by bracts. The two seed leaves ( cotyledons ) are thick and fleshy.

Chromosome number

The chromosome number is 2n = 16

Systematics and distribution

The genus Ostryopsis occurs only in northern China.

The first description of the genus Ostryopsis in 1873 by Joseph Decaisne in Bulletin de la Société Botanique de France, vol 20, p 155 The type species is Ostryopsis davidiana Decne .. The genus Ostryopsis Decne. belongs to the subfamily Coryloideae in the family Betulaceae. Previously, she was placed into these families Carpinaceae or Corylaceae.

The genus Ostryopsis are only three ways:

• Ostryopsis davidiana Decne. Thrives in open woods and in bushes at altitudes 800-2800 m in Gansu, Hebei, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shanxi and western Sichuan. It is used to control soil erosion and agricultural equipment from the branches are made.
• Ostryopsis intermedia B.Tian & JQLiu: It was described in 2010 in Botanical Studies, Volume 51, ​​page 261, Figure 1. It occurs only at altitudes 1500-2500 meters in the northwestern Yunnan.
• Ostryopsis nobilis Balf. f & WWSm. thrives in bushes on sunny mountain slopes at altitudes between 1500 and 3000 meters in the southwestern Sichuan and northwestern Yunnan.

Swell

• Pei -chun Li & K. Alexei Skvortsov: Betulaceae: Ostryopsis, pp. 289 - text the same online as printed work, In: Wu Zheng -yi and Peter H. Raven (Editor): Flora of China, Volume 4 - Cycadaceae through Fagaceae, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 1999. ISBN 0-915279-70-3 (Section Description, systematics, distribution and use )