Angraecum sesquipedale is an Angraecum species endemic to the Madagascar.
Star-like flowers are produced on inflorescences arising from the stem each December. This flowering habit is what lends the orchid several of its common names. Flowers are fragrant.
This orchid is well-known within the botany community, especially for its association with the English naturalist Charles Darwin (1809-1882). Darwin observed A. sesquipedale while in Madagascar during his five year voyage on the Beagle. Darwin noted the defining characteristic of the species: its extremely long spur. The spur of the flower is 20-35 cm from its tip to the tip of the flower's lip.
From his observations, Darwin surmised that there must be a pollinator moth with a proboscis butterfly species long enough to reach the nectar at the end of the spur. In its attempt to get the nectar and the end of the spur the moth would get pollen rubbed off on its head. The next orchid it visited would then be pollinated in the same manner.
More than fifty years after Darwin's 1862 publication "On the various contrivances by which British and foreign orchids are fertilised by insects" in which he discussed his hypothesis, such a moth was discovered in Madagascar. Xanthopan morganii praedicta has been recently observed pollinating Angcm. sesquipedale. The epithet "praedicta" was given in honor of the fact that Darwin predicted its existence. The moth approaches the flower to ascertain by scent whether or not it is the correct orchid species. Then the moth backs up over a foot and unrolls its proboscis, then flies forward, inserting it into the orchid's spur.
Angcm. sesquipedale is seldom grown in private collections, despite its enormous importance to Darwin's concept of co-evolution and subsequently the fields of botany and evolutionary biology.
Plant is found on sloping trees in the tropical forest of Madagascar at elevations of 0 to 100 meters.
Grow in bright diffused light and intermediate to hot conditions. Grow in medium fir bark or full sphagnum moss. Water regularly.
The name "sesquipedale" is Latin for "one and a half feet," referring to the spur length.
Common Names: Darwin's orchid, Comet Orchid, Christmas orchid, Star of Bethlehem orchid
- Aeranthes sesquipedalis[Thou]Lindley 1824
- Aeranthus sesquipedalis[Thou]Lindley
- Angorchis sesquipedale [Thou]O.Ktze. 1891
- Angraecum bosseri Senghas 1973
- Angraecum sesquipedale var. angustifolium Bosser & Morat 1972
- Macroplectrum sesquipedale [Thou]Rolfe
- Macroplectrum sesquipedale[Thou.] Pfitz. 1889
- Mystacidium sesquipedale Rolfe 1904