Angrekum one and a half feet - the star of Madagascar
One and a half feet Angrekum ( Angraecum sesquipedale ) - a perennial herbaceous plant of the Orchidaceae family ( Orchidaceae ). The species does not have an established Russian name, in the Russian-language sources the scientific name Angraecum sesquipedale is more often used.
History of the description and etymology of Angrekum one and a half feet
The first European to find this species was the French botanist Louis Marie Aubert Du Petit-Thouars (in French) in 1798, but the plant was not described until 1822.
The generic name is derived from the Malaga. angurek - used in relation to many local Wand orchids; specific name from lat. sesqui - half and a half times lat. pedalis - foot, the size of a Roman foot, in relation to the length of the spur.
The English name is Comet Orchid (comet orchid). The French name is Étoile de Madagascar (the star of Madagascar).
Biological description of Angrekum one and a half feet
Monopodial plants of large sizes. The stem is erect, 70-80 cm high. The leaves are dense, leathery, with a bluish waxy coating, folded at the base, obtuse, slightly wavy along the edge, two-rowed, 30-35 cm long, 3-4 cm wide. Powerful aerials are rarely located on the stem the roots are initially greenish-silvery, and later greenish-brown.
Peduncles slightly articulated, shorter than the leaves. In inflorescence 2-6 large flowers. The flowers resemble a star in shape, up to 15 cm in diameter with a long spur, have a strong night aroma. Color is white or creamy white. Bracts are short, ovoid. Sepals are triangular-lanceolate, 7–9 cm long, 2.5–3 cm wide. Arrow-shaped petals, bent backward, 7–8 cm long, 2.5–2.8 cm wide. Lip is elongated-lanceolate, pointed, with a long , up to 25-30 cm, light green spur. The column is thick, 1-1.5 cm long.
Chromosomes: 2n = 42
This species of Angrekum is well known thanks to Charles Darwin and his book "On the Adaptation of Orchids to Insemination by Insects", published in 1862.
Examining a 1.5-foot Angrekum flower sent to him from Madagascar, Darwin drew attention to a very long spur of 11.5 inches with nectar at the very bottom and suggested that this species had its own pollinator, most likely a large nocturnal shred with a corresponding long proboscis spur. However, the famous entomologists of those times only laughed at the vision of the scientist. In 1871, Alfred Russell Wallace came to the same conclusion and suggested that Angrekum one and a half feet could be pollinated by Xanthopan morgani, found in tropical Africa.
In 1903, after Darwin's death, a subspecies Xanthopan morgani with a wingspan of 13-15 cm was finally discovered in Madagascar, and a proboscis about 25 cm long, Entomologists called this subspecies Xantopan morgani praedicta . The word lat. prae – dico means "foretold."
Habitat and ecological features of Angrekum one and a half feet
Endemic of the island of Madagascar. In the recent past, it was found in abundance in the coastal thickets of the Pangalan canal, located along the coast of the Indian Ocean, in the eastern part of Madagascar, as well as on the island of Nosy Burakh, at heights of up to 100 meters above sea level.
At present, the natural population of this species is sharply declining, despite attempts at reverse reintroduction.
Belongs to the number of protected species (II CITES appendix). The purpose of the Convention is to ensure that international trade in wild animals and plants does not endanger their survival.
Epiphytic, rarely lithophytic plants, often forming dense groups. It grows on inclined trunks or in the forks of tree branches in the lower tier of the forest, on rocky outcrops, and occasionally as a land plant. The second largest among the representatives of the Angrekum clan; the largest representative of the genus - Angraecum eburneum var. superbum.
It blooms in nature from June to November.
The climate on the east coast of Madagascar is humid, tropical. Rains continue year round.
Average temperatures from January to February 25 ° C; March to April 30 ° C; from May to July - from 20 to 25 ° C; from August to September 15 ° C; from October to November - from 20 to 25 ° C; December 30 ° C.
Angrekum one and a half feet in culture
Instances seized from nature, first came to England in 1855. The first flowering in the culture was obtained in the collection of William Ellis in 1857. The first hybrid featuring Angraecum sesquipedale was created by John Seden, an employee of the Veitch Nurseries cattery, and was first exhibited on January 10, 1899. It was named Angraecum Veitchii, but is also widely known under the name King of the Angraceum hybrids.
The temperature group is moderate.
Planting in baskets for epiphytes or light (not heating up in the sun) plastic pots. The substrate must not impede the movement of air. Several stones are laid at the bottom of the pot making the pot more resistant to capsizing, the main substrate is a large bark of pine (5-6 cm) and pieces of polystyrene or expanded clay in a 1: 1 ratio. The upper layer of the substrate consists of a middle fraction bark (2-3 cm); in addition, sphagnum or another type of moss can be added to the upper part of the substrate.
It does not have a pronounced resting period. In winter, watering is slightly reduced. The frequency of watering during the growing season should be selected so that the substrate inside the pot has time to dry out almost completely, but does not have time to dry out completely. The plant is sensitive to the accumulation of salts in the substrate. With salinization of the substrate at the ends of the lower leaves, and if timely measures are not taken, then brown spots of necrosis begin to appear. Over time, these spots grow and lead to a fairly rapid death of leaf blades. For irrigation, it is better to use water that has been purified by reverse osmosis.
Relative humidity 50-70%. Low humidity (less than 45%) in the room can lead to partial sticking of new leaf blades, which subsequently take a slightly boat-like shape.
Lighting: 10-15 kLk. Be sure to shade from direct sunlight. Despite its seemingly well-protected, wax-coated leaves, the plant, left unattended for several hours under direct sunlight, easily gets severe burns. With insufficient lighting, the plant does not bloom.
Transplantation every 1-3 years, depending on the degree of decomposition of the substrate. Fertilizing with complex fertilizer for orchids in a minimum concentration of 1-3 times a month.
Young plants are damaged by several species of ticks of the genus Tetranychus (Tetranychus urticae, Tetranychus turkestani, Tetranychus pacificus, Tetranychus cinnabarinus). Adult specimens can be affected by scale insects - insects belonging to the Diaspididae family, and pseudoscutis (insects of the Coccidae family, or Lecaniidae), which settle in the axils of the lower leaves and on the bare part of the stem.
For more, see the article Pests and diseases of orchid indoor soil.
The beginning of budding in November. Flowering - December-February. The duration of flowering is 3-4 weeks, 2.5-3 weeks remain in the slice. At home, sometimes blooms twice a year; in January and closer to mid-summer.
Diseases and Pests
Young plants are easily damaged by a red tick. Adult specimens are well protected from the mite with a wax coating on the leaves, however, they often settle on the scab, which at first can be found in the axils of the lower leaves and on the bare part of the stem. If protection measures are not taken in time, the scabbard gradually settles on the lower sides of all leaves, localizing along the central vein and closer to the tips.
It is especially unpleasant to see a peduncle densely covered with scabies. Timely removal of all adult scale insects followed by insecticide treatment will save your plant from these insects.
Angrekum hybrids one and a half feet
Intrageneric primary hybrids (greksy)
Angraecum Appalachian Star - A.sesquipedale x Angraecum praestans - Breckinridge, 1992.
Angraecum Crestwood - A.Veitchii x A.sesquipedale - Crestwood, 1973.
Angraecum Dianne's Darling - A.sesquipedale x A. Alabaster - Yarwood, 2000.
Angraecum Lemförde White Beauty - Angraecum magdalenae x A.sesquipedale - Lemförder Orch., 1984.
Angraecum Malagasy - A.sesquipedale x Angraecum sororium - Hillerman, 1983.
Angraecum Memoria Mark Aldridge - A.sesquipedale x Angraecum eburneum subsp. superbum - Timm, 1993.
Angraecum North Star - A.sesquipedale x Angraecum leonis - Woodland, 2002.
Angraecum Ol Tukai - Angraecum eburneum subsp. superbum x A.sesquipedale - Perkins, 1967
Angraecum Orchidglade - A.sesquipedale x Angraecum eburneum subsp. giryamae, J. & s., 1964.
Angraecum Rose Ann Carroll - Angraecum eichlerianum x A.sesquipedale - Johnson, 1995
Angraecum Sesquibert - A.sesquipedale x Angraecum humbertii - Hillerman, 1982.
Angraecum Sesquivig - Angraecum viguieri x A.sesquipedale - Castillon, 1988.
Angraecum Star Bright - A.sesquipedale x Angraecum didieri - H. & R., 1989.
Angraecum Veitchii - Angraecum eburneum x A.sesquipedale - Veitch, 1899.
Intergeneric hybrids (greksy)
Eurygraecum Lydia - A.sesquipedale x Eurychone rothschidiana - Hillerman, 1986.
Eurygraecum Walnut Valley - Eurygraecum Lydia x Angraecum magdalenae - R. & T., 2006.
Angranthes Sesquimosa - Aeranthes ramosa x A.sesquipedale - Hillerman, 1989.