Przewalskia tangutica
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Przewalskia | ||||||||||||
| Maxim. | ||||||||||||
| Scientific name of the species | ||||||||||||
| Przewalskia tangutica | ||||||||||||
| Maxim. |
Przewalskia tangutica is the only species of the genus Przewalskia inthe nightshade family (Solanaceae). The species occurs only in a limited area in China . It was first described by Karl Johann Maximowicz in 1881. The generic name honors the Russian military officer, naturalist and geographer Nikolai Michailovich Przewalski (1839 - 1888).
description
Vegetative characteristics
Przewalskia tangutica are herbaceous plants with perennial, fleshy roots that can be up to 3 cm thick. The plant is richly covered with glandular trichomes , which consist of a two- to three-celled stem and a multicellular head. The stem axis is very short with 5 to 30 cm, it is partly underground and there covered with scale-like leaves. The aboveground part has very short internodes , so that the plant appears rosette-shaped. The leaves stand on petioles 2 to 5.5 cm long, the leaf blades have a length of 10 to 17 cm and a width of 1 to 4.5 cm, they are oblong-spatulate or egg-shaped.
Inflorescences and flowers
The flowers appearing in June / July are in clusters of one to three (six) flowers in the armpits on very short peduncles with a length of 5 to 10 mm. The radially symmetrical calyx is cylindrical-bell-shaped and has a length of 10 to 15 mm - about half the length of the corolla tube. The calyx has five triangular, pointed lobes that are 1/6 to 1/7 the length of the calyx tube. The tubular crown is radially symmetrical and 20 to 26 mm long. The corolla lobes are elliptical or ovate, longer than wide and about 4 mm long. The stamens are of the same shape, protrude beyond the corolla tube, the stamens are shorter than the anthers. The stamens are fused with the corolla tube near the distal end of the corolla tube, they attach to the anthers distally. The anthers are about 1.5 mm long. The pollen is tricolated, almost spherical and medium-sized at 39 to 40 µm. The scar protruding over the crown is disc-shaped and head-shaped, circular nectaries are formed.
Fruits and seeds
By the time the fruit ripens in July to September, the calyx enlarges to a length of 8 to 13 cm and a diameter of 4 to 6.5 cm and assumes an urn-shaped to egg-shaped shape and becomes almost leathery. In the calyx a special form of the dry capsule fruit called pyxidium develops . This has a diameter of 10 to 15 mm. The kidney-shaped seeds are black-brown and 3 mm long and 2.5 mm wide. The embryo is strongly curved, the cotyledons shorter than the rest of the embryo, the endosperm is abundant.
Chromosome number
The number of chromosomes is 2n = 44.
distribution
Przewalskia tangutica is endemic to cold and arid areas in western China , mainly the so-called Qinghai - Xizang Plateau. It prefers sandy soils at altitudes between 3200 and 5000 m above sea level.
use
The root is used as a medicinal herb for muscle cramps, pain, and swelling.
literature
- Zhang Zhi-yun, Lu An-ming, William G. D'Arcy: Przewalskia tangutica . In: Flora Of China , Vol. 17, page 306.
- Armando T. Hunziker: The Genera of Solanaceae . ARG Gantner Verlag KG, Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 .
Individual evidence
- ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. [1]
- ^ Przewalskia tangutica at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis