Angraecum sesquipedale
| Angraecum sesquipedale | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
" Star of Madagascar " |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Angraecum sesquipedale | ||||||||||||
| Thouars |
Angraecum sesquipedale , sometimes also called star of Madagascar or star orchid , is a species of the orchid family (Orchidaceae) thatis nativeto the east coast of Madagascar as an epiphyte or lithophyte . What is particularly noticeable about this orchid is the lip spur, which is over 40 cm long and in the lower part of which nectar is produced. Angraecum sesquipedale has attracted particular scientific attention, as Charles Darwin had proposed, based on a plant cultivated in England, that theremust bea butterfly in Madagascar with an extremely long proboscis that pollinates this plant. Thirty years later (1903) the Malagasy subspecies of a known already from Africa was enthusiast rewritten, was true to this forecast. It was scientifically described under the name Xanthopan morgani praedicta ( Latin praedictus "the predicted") at a time when Charles Darwin was long dead. The flower visit by the hawker could not be documented photographically for the first time until 1997. A time estimate based on molecular clocks shows that the Malagasy subspecies of the hawkmoth and the orchid Angraecum sesquipedale are both around 7 million years old (Netz and Renner, 2017).
description
Angraecum sesquipedale is a monopodial , up to one meter high plant with a thick, leafy, strong trunk. The belt-shaped, leathery leaves are up to 30 cm long and 4 to 5 cm wide. The two- to six-flowered inflorescences are shorter than the leaves. The star-shaped, fleshy flowers are about 12 cm in diameter and have a strong scent at night. Their color is white to cream. The egg-shaped lanceolate sepals (sepals) (outer tepals ) are 7 to 9 cm long and 2 cm wide. The petals (inner tepals) are shaped similarly to the sepals, about 7 to 8 cm long and 2.5 to 3 cm wide. The lip (labellum) is 6 to 8 cm long, 3.5 to 4 cm wide, hollow, violin-shaped, bluntly pointed and encompasses the column (gynostemium) at the base . A narrow spur entrance leads to the up to 45 cm long, downward-hanging and curved spur.
The flowering time in Madagascar is between June and November.
Angraecum sesquipedale has a chromosome number of 2n = 38, 42.
distribution
The occurrence of Angraecum sesquipedale is limited to the coastal forest on the east side of the island of Madagascar up to a height of 100 m. It does not occur in the northernmost part of the island.
Systematics
Angraecum sesquipedale was from you Louis Marie Aubert Petit-Thouars discovered (1758-1831) and in 1822 in the work Histoire des Plantes particulière orchidées recueillies sur les trois Iles australes d'Afrique first described . The epithet sesquipedale means “ foot and a half ” and alludes to the length of the spur.
The following additional descriptions of this type are considered synonyms :
- Aeranthes sesquipedalis (Thouars) Lindl. (1824)
- Macroplectrum sesquipedale (Thouars) Pfitzer (1889)
- Angorchis sesquipedalis (Thouars) Kuntze (1891)
- Mystacidium sesquipedale (Thouars) Rolfe (1904)
literature
- H. Bechtel, Ph. Cribb, E. Launert: Orchideenatlas. Ulmer, Stuttgart 1993 (3rd edition). ISBN 3-8001-6199-0
- R. Schlechter: The orchids. 4 vol. & Reg. Revised K. Senghas. Blackwell-Wiss.-Verl., Berlin / Vienna 2003 (3rd edition). ISBN 3-8263-3410-8
- K. Senghas: Orchids: Plants of extremes, opposites and superlatives. Parey, Berlin Hamburg, 1993. ISBN 3-489-64024-1
- Christoph Netz and Susanne S. Renner: Long-spurred Angraecum orchids and long-tongued sphingid moths on Madagascar: A time-frame for Darwin's predicted Xanthopan / Angraecum coevolution . Biological Journal of the Linnean Society 122, 2017, doi : 10.1093 / biolinnean / blx086
Individual evidence
- ↑ LT Wasserthal: The Pollination of the Malagasy Star Orchids Angraecum sequipedale, A. sororium and A. compactum and the Evolution of the Extremely Long Spurs by Pollinator Shift. Botanica Acta 110, 1997, pp. 343-359
