Taraxacum kok-saghyz
Russian dandelion (Taraxacum kok - saghyz )
Russian dandelion (Taraxacum kok - saghyz ) is a species of the genus dandelion (Taraxacum ) in the sunflower family ( Asteraceae). She is originally from Kazakhstan and western Xinjiang. This species is intensively researched for time to extract natural rubber.
- 4.1 rubber replacement
- 4.2 Other Use
- 5.1 Literature
- 5.2 Notes and references
Description
Appearance and foliage leaf
Russian dandelion is a perennial herbaceous plant that reaches the plant height 4-15 cm. It contains in all parts of a white milky sap. It is formed a taproot.
The leaves are borne in a basal rosette. The petiole is pale green and winged. The simple, bluish - grayish - green, more or less fleshy leaf blade is at a length of 3 to 7 ( to 10 ) cm and a width of 1.2 to 3 cm narrow to broad - lanceolate wrong. The leaf margin is serrated away to regularly lobed to pinnately lobed. Two or three, and five pairs of side flaps are often broadly triangular. The leaf blade has at most a few spider-shaped hairs ( trichomes ) or is bald.
Inflorescence and flower
The flowering period extends into China from late spring to early summer. The light green to pink inflorescence stem spheric spider-shaped hair and towers over the leaves more or less. The basket- shaped inflorescence has a diameter of 2 to 3 cm. The non- tile- shaped stacked 8 to 13 outer bracts are pale green, sometimes even in the light purple appearing and ovate-lanceolate to narrowly ovate. The outer bracts are mm shorter than the inner bracts with a length of 5.5 to 7 mm and a width of 1.2 to 2.2 ( 1 to 2.5 ). They are lightly pressed to erect, the margin is whitish light green or membranous. The inner bracts are 8-12 mm long with a thin 1-2 mm long horn at the top. The ray florets are bright yellow, the inner yellow are perforated at the top. The scars are deep yellow.
Fruit
The light - grayish straw brown achene narrows at a length from 2.8 to 3.8 mm and a width of 0.7 to 0.9 mm gradually to an almost cylindrical, cone-like shape. They are more or less densely spined, and are cone-shaped with a flattened 3 to 4.5 mm long beak. The white Pappus has a length of 3.5 to 4.5 mm.
Chromosome number
The chromosome number is 2n = 16 in a diploid set of chromosomes.
Occurrence
The original home is Kazakhstan and western Xinjiang.
Russian dandelion prefers sandy to loamy and clayey soils, the well drained, but moist. It can grow in acidic, neutral and even strongly alkaline soils. It grows well in partial shade, as well as in full daylight.
Taxonomy
The first description of Taraxacum kok - saghyz was made in 1933 by Leonid Efimovic Rodin in Trudy Akademii Nauk SSS Botanicheskogo Instituta R., Ser. 1, in: Flora i Sistematika Vysshikh Rastenii. Moscow & Leningrad, 1, pp. 187-189, Figure 1-10. A synonym for Taraxacum kok - saghyz Rodin is Taraxacum brevicorniculatum Korol ..
The specific epithet kok - saghyz derives from the Turkish kok - sagiz, the Turkish words kok root and sagiz rubber mean.
Use
Russian dandelion was discovered in the thirties of the 20th century in Kazakhstan, as was looking for a local source of rubber in the former Soviet Union. In 1941 30% of the Soviet rubber consumption was produced on 67,000 ha. In other countries it has been researched and grown, so also in the German Reich under the project Kok sagyz. Among other things, in 1942 a research station for rubber plants set up in the Auschwitz concentration camp, in the 150 to 250 forced laborers were employed. After the Second World War, he was soon ousted from Hevea brasiliensis, in the Soviet Union. Only in recent years, he is pulled back as a rubber substitute into consideration.
Rubber replacement
After the Second World War forgotten, the Russian dandelion is again regarded as potential raw material for rubber plant for several years and studied in Europe and North America. The aim of the research is to gain from the Russian dandelion dandelion rubber usable as an alternative to commonly used today natural rubber from the milk sap of the rubber tree (Hevea brasiliensis) and synthetic rubber. Thus, the Russian dandelion provides 1 milliliter of rubber per plant. Additionally, the short life cycle of six to eight months, and the possibility of tissue cultures offers additional advantages over other potential source of rubber. The rubber particles which are recovered from the Russian dandelion, which from Hevea brasiliensis are very similar. They contain very pure poly (cis -1 ,4- isoprene) with a high molecular mass.
Others use
The main active ingredients are sesquiterpene lactone - bitters ( Tetrahydroridentin B, Taraxacolid - β -D - glucodid and others), a phenol carboxylic acid derivative ( Taraxosid ), and triterpenes ( taraxasterol and its derivatives ) and inulin. This is the Russian dandelion an interest for the pharmaceutical industry dar.