Pogonia japonica
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Pogonia japonica |
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The orchid Pogonia japonica is a species of plant found in East Asia.
description
Pogonia japonica grows to 10 to 20 cm, rarely up to 25 cm. The rhizome grows upwards, it measures 2 mm in diameter, the length of the internodes depends on the substrate and ranges from 0.5 to 2.5 cm. A thin root arises per internode . The roots can form adventitious shoots at a distance . On the rhizome there is alternating a lower leaf and a leaf- bearing shoot. The leaf is inversely ovate to spatulate, it is up to 10 cm long and 1.5 cm wide.
The terminal inflorescence consists of only one flower . The bract is 2 to 4 cm long, 3 to 7 mm wide and leaf-like. The flowers are resupinated , the color is pink. The petals are about 2.5 cm long and 0.5 cm wide, the lip is slightly larger and indistinctly three-lobed, the front edge is fringed, there are dense, yellow-colored appendages on the lip. The column is slender, about 1 cm long. The capsule fruit stands upright, it becomes about 2 cm long and 0.5 cm wide.
The number of chromosomes is usually 2n = 18 or 2n = 20, more rarely numbers up to 2n = 23, occasionally even 36, 62 or 68 are mentioned.
Occurrence
Pogonia japonica is native to East Asia. It occurs in China, Japan, Korea and in Far Eastern Russia and can be found at altitudes of 2300 meters.
The locations are mostly sunny and humid, such as wet meadows, swamps and moors. The soil is acidic and poor in nutrients.
Life cycle
The following on germination Protokorm stage created was at Pogonia japonica not been observed. The primary shoot grows monopodially for one to three years until it develops a first leaf. The first flowering occurs after another two to three years. Under unfavorable conditions this can take up to five years, the shoot then often dies after flowering, while the plants in favorable locations can bloom for three to four years in a row.
The leaves shoot depending on the climatic conditions in spring or in autumn. The flowering period extends from May to July, in the north of the distribution area also to August. The flowers are pollinated by various bumblebees ( bombus ). The plants produce neither fragrance nor nectar, so the bumblebees are being fooled. However, some insects eat the appendages on the lip. In some populations, the bumblebees confuse Pogonia japonica with the similar Japanese iris ( Iris ensata ) and visit the orchid flowers. The fruit ripeness extends from July to October, depending on the location. The capsule fruit contains around 2000 seeds.
In addition to generative reproduction, almost all individuals form abundant new shoots at the ends of the roots and thus reproduce vegetatively. The shoots formed in this way resemble young plants and also need a few years to bloom.
Mycorrhizal fungi are only present with low intensity in adult plants. Ceratobasidium cornigerum and Rhizoctonia repens were isolated from older roots .
literature
- MG Vakhrameeva, IV Tatarenko, TI Varlygina, GK Torosyan, MN Zagulskii: Orchids of Russia and Adjacent Countries . ARG Gantner, Ruggell 2008, ISBN 978-3-906166-61-2 , p. 420-424 .
- Chen Xinqi, Stephan W. Gale, Phillip J. Cribb: Orchidaceae (Draft) . In: Wu Zhengyi, Peter H. Raven, DY Hong (eds.): Flora of China . tape 25 . Missouri Botanical Garden Press, St. Louis ( Flora of China [accessed April 25, 2009] 1994+).
Individual evidence
- ↑ Rafaël Govaerts (ed.): Pogonia japonica. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 1, 2020.
