Gossypium arboreum
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| Gossypium arboreum L. |
Gossypium arboreum, commonly called tree cotton, is a species of cotton native to India and Pakistan and other tropical and subtropical regions of the Old World. There is evidence of its cultivation as long ago as 2000 BC by the Harappan civilization of the Indus Valley for the production of cotton textiles. This species of cotton was introduced into East Africa by about 2000 years ago, and was grown by the Meroe civilization in Nubia, the first cotton weavers in Africa.[citation needed] The shrub was included in Linnaeus's Species Plantarum published in 1753. The holotype was also supplied by him, which is now in the Linnean Herbarium in the Swedish Museum of Natural History.[1]
[edit] Description
Tree cotton is a shrub attaining heights of 1 to 2 metres. Its branches are covered with pubescence and are purple in colour. Stipules are present at the leaf base and they are linear to lanceolate in shape and sometimes falcate (i.e. sickle-shaped). The leaves are attached to the stem by a 1.5 to 10 cm petiole. The blades are ovate to orbicular in shape and have 5 to 7 lobes, making them superficially resemble a maple leaf. The lobes are linear to lanceolate, and often a tooth is present in the sinus. Glands are present along the midrib or occasionally on the adjacent nerves. The leaves are glabrescent, meaning the pubescence is lost with age, but when it is present on young leaves, it is both stellate (i.e. star-shaped) and simple.[1]
The flowers are set on short pedicels (i.e. flower stalks). An epicalyx is present, which is a series of subtending bracts that resemble sepals. It has large, ovate segments that are dentate (i.e. toothed along the margins), though sometimes only very slightly so. They are cordate (i.e. heart-shaped) at the base and acute at the apex. The true calyx is small, measuring only about 5 mm in length. Its shape is cupular, and there are 5 subtle dentations present. The corolla is a pale yellow on colour, sometimes with a purple centre, and occasionally entirely purple. It measures 3 to 4 cm in length. The staminal tube bears the anthers and is 1.5 to 2 cm in length. The fruit is a 3 to 4 celled capsule measuring 1.5 to 2.5 cm across. It is ovoid or oblong in shape and glabrous (i.e. hairless). The surface is pitted and a beak is present at the termnial end. The seeds within are globular and are covered in long white cotton.[1]
[edit] References
- ^ a b c Abedin, Sultanul (1979), “Gossypium arboreum”, in Ali, S.I.; Qaiser, M., Flora of Pakistan, vol. 130, St. Louis: University of Karachi & Missouri Botanical Garden, pp. 30
[edit] External links
Media related to Gossypium arboreum from the Wikimedia Commons.
