Aesculus
Horse-chestnut (Aesculus hippocastanum)
The horse chestnut (Aesculus ) are a genus of flowering plants in the family of Soapberry ( Sapindaceae ). The genus includes about 12 species in North America, Europe and Asia. In Europe, the Horse Chestnut is widely planted as park and street tree. A partial name match with the sweet chestnut (Castanea sativa) is based on a superficial similarity of the fruit, not on kinship; both belong to different families.
Description
The representatives of the Buckeyes are deciduous trees or shrubs. The winter buds are large, often rich in resin and consist of several pairs of imbricaten shed. The outside of the shed is bald or slightly hairy.
The leaf blade is feathered finger-shaped and consists of five to eleven leaflets. The leaflets have a serrated to dentate margin.
The inflorescences are cylindrical to conical thyrsi with simple side branches. Bracts absent. The flowers are usually large and conspicuous. The sepals are fused to form a tube- to bell-shaped calyx tube. The petals are often unequal. They are nailed, the plate is obovate, lanceolate or spatulate. The ovary is not on a Gynophor, the pen is long and slender, the stigma compressed globose, sometimes slightly lobed. The fruit is a spherical to pear-shaped capsule, often containing a seed. The pericarp is usually smooth, rarely wrinkled or spiny, the latter in the ordinary horse chestnut. The seeds are like the capsule globose to pear-shaped, and 2-7 inches tall. The seed coat is brown, the navel ( hilum ) is large, pale and occupies one third to one half of the seed.
The basic chromosome number x = 20 leaves, flowers and seeds contain the toxic substance aescin.
Distribution and habitat requirements
The genus Aesculus native to the northern hemisphere and here comes predominantly in the temperate climate zone. The distribution of the genus is fragmented ( disjoint ) and is divided into three sub-regions: North America come in several types of the front west to the east coast. One type, the Horse-chestnut is native to southeast Europe, but widely planted in Europe. Several species occur in East Asia from the Himalayan region over Southeast Asia and China to Japan before.
System
Buckeyes are represented by the natural location in Europe with only one way in Asia and North America, there are numerous types.
The genus is divided into several sections:
- Section Parryanae Aesculus parryi A. Gray, endemic to Mexico
- Japanese horse chestnut (Aesculus turbinata Blume), endemic to Japan
- Horse-chestnut (Aesculus hippocastanum L. ), endemic in the Balkans, widespread in Europe planted
- California buckeye (Aesculus californica ( Spach ) Nutt. ), Endemic to California
- Aesculus assamica handle. , In Southeast Asia
- Chinese horse chestnut (Aesculus chinensis Bunge ) in China
- Indian horse chestnut (Aesculus indica ( wall. ex Camb. ) Hook. )
- Aesculus wilsonii Rehder, was founded in 2005 to Ae. chinensis asked and no longer operate as a separate type.
- Shrub buckeye (Aesculus parviflora Walter ), endemic in Georgia and Alabama
- Ohio buckeye (Aesculus glabra Willd. ), In the southeastern U.S.
- Yellow buckeye (Aesculus flava Sol., Formerly Aesculus octandra Marshall), in the southeastern U.S.
- Aesculus sylvatica W. Bartram, in the southeastern U.S.
- Red Buckeye (Aesculus pavia L.), United States.
For the Buckeyes, there are numerous species hybrids, some of which have a meaning as ornamental trees, such as the meat Red Horse Chestnut ( Aesculus x carnea Hayne, Ae. Hippocastanum × Ae. Pavia ).
Naming
The genus name Aesculus was transmitted only by Carolus Linnaeus to the Buckeyes. In ancient times was called the Latin word aesculus a species of oak, which was sacred to Jupiter, grew up mountains, was of great stature and solid wood. The word referring possibly to the Sessile Oak (Quercus petraea )
The German name actually refers to the horse chestnut Horse-chestnut. It is based on the chestnut -like seeds that were carried by the Ottomans as horse feed and as a remedy for coughs and horses came so to Central Europe. This served to differentiate these inedible for humans have long known the seeds of edible sweet chestnuts.