Chestnut
The sweet chestnut (Castanea sativa)
The chestnut (Castanea ) and sweet chestnuts are a genus in the beech family ( Fagaceae ). The genus is widespread with about twelve tree and shrub species in the north temperate zone. In Europe, only the sweet chestnut (Castanea sativa ) is native.
Horse Chestnut (Aesculus ) are a diverse genus of the chestnut. The partial name matching is based on the superficial similarity of the fruit to the fruit stand of chestnut ( brown core in spiny shell ) and not on botanical relationship.
Description
The chestnuts are trees or shrubs. The bark is furrowed and oak similar. The branch is sympodial: the terminal bud of each branch dies, the growth assumes a lateral bud. The buds are surrounded by three to four bud scales.
The leaves are alternate, side branches, they are apparently two lines. The leaf shape is oblong -elliptic to broadly lanceolate, the blade tip is usually tapered or pointed. The numerous secondary nerves run parallel. They are recessed at the top, projecting at the bottom. The leaf margin is serrated, the teeth often wear a sting Spitz. Stipules are present. The chestnuts are leaves- throwing, the fall color is yellow.
All species are monoecious dioecious ( monoecious ), that is on a plant are female and male flowers exist.
The male flowers are in little head like part inflorescences on long, upright catkins. They have a simple perianth of a six -divided perianth. The outside is often densely hairy, but can be almost bald. The 10 to 12 stamens have long filaments. The anther are small, have two counters and open with a longitudinal slot. In the center of the flower is a stamp - rudiment.
The female flowers are sessile and are usually three to a prickly involucre. These are located at the base of male catkins. The perianth is hairy six parts as in the male flowers and the outside. The ovary is four to siebenfächrig, inferior and exterior bare. The 4 to 10 pens are needle-shaped, hairy at the base and wear pointed scars.
The nut fruits are large, brown. Their shape is round or flat - convex at the base, they have a conspicuous scar. One to seven, usually three nuts located in the spiny fruit cup ( cupula ), which has evolved from the involucre. The spines of the pericarp are hairy.
Dissemination
The genus is native to the temperate areas of the northern hemisphere. The area is divided into three sub- areas fragmented ( disjoint ): some species are found in eastern North America; the chestnut tree in the Mediterranean region and the north adjacent areas; the other species in East Asia (especially China and Japan).
Use
The three types of sweet chestnut, Japanese and Chinese chestnut grown for nuts. The wood is also used; the sweet chestnut is resistant to weathering and no preservatives. Some species, like the shrub, grown as ornamental plants.
System
Within the genus eight to twelve types are distinguished depending on the author. The following list follows Breisch 1995:
- Section Eucastanon with three fruits per cupula American chestnut ( Castanea dentata ) in North America
- Sweet chestnut (Castanea sativa) in Europe
- Japanese chestnut ( Castanea crenata ) in Japan
- Chinese chestnut (Castanea mollissima) in China
- Castanea seguinii in China
- Castanea henryi in China
- Castanea ozarkensis in USA
- Castanea ashei in USA
- Castanea floridana in USA
- Castanea pumila in USA
- Castanea alnifolia in USA
- Castanea paucispina in USA
The last five types of list, however, by Govaerts (1998) summarized as a kind of Castanea pumila.
The species also form hybrids with each other, some of which are also grown.
Paleobotany
Chestnut Similar inflorescences are known from the Middle Eocene of Tennessee; chestnut- like wood is fairly common in the Eocene and Miocene. The leaves of Castaneopyllum (formerly form genus Dryophyllum ) are simple, schmallanzettliche leaves up to 28 centimeters in length. The lateral nerves end at the leaf margin. This type of blade is considered by some authors as the original for the family.
Documents
The article is based on the following documents:
- Species description in the Flora of Taiwan, Volume 2, pp. 52f.