Lemon eucalyptus
| Lemon eucalyptus | ||||||||||||
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Lemon eucalyptus ( Corymbia citriodora ) with freshly sprouted leaves |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Corymbia citriodora | ||||||||||||
| ( Hook. ) KDHill & LASJohnson |
The lemon eucalyptus ( Corymbia citriodora ) is a species of the genus Corymbia within the myrtle family (Myrtaceae). It occurs on the east coast of Australia , from northern Queensland to northeastern New South Wales and occasionally in Victoria and South Australia . and is called there “Lemon-scented Gum” or “Spotted Gum”.
description
Appearance and leaf
The lemon eucalyptus grows as a tree that reaches heights of up to 30 or 50 meters. It forms a lignotuber . The bark is smooth, powdery white, gray, pink, creamy white or copper colored all over the tree and peels in polygonal patches. There are oil glands in the pith and in the bark.
At Corymbia citriodora is Heterophyllie ago. The leaves are always divided into a petiole and a leaf blade. The leaf blade on young specimens is 14 to 21 centimeters long and 4.5 to 8 centimeters wide and lanceolate to ovate and has simple hairs and stiff glandular hairs. The leaf blade on medium-old plants is lanceolate to elliptical, straight, entire and dull green. The leaf stalk on adult specimens is 1 to 2.5 inches long and narrowly flattened or channel-shaped. The leaf blade of the same color on the upper and lower side of the leaf on adult specimens is relatively thin, with a length of 7 to 23 centimeters and a width of 0.6 to 3.5 centimeters narrow-lanceolate to lanceolate, straight or sickle-shaped, with itself tapered spreading base and pointed upper end. The side nerves, which are barely recognizable, branch off from the median nerve at small intervals at an acute or obtuse angle. On each half of the leaf there is a pronounced, continuous, so-called intramarginal nerve, which runs at a small distance along the edge of the leaf. The cotyledons ( cotyledons ) are almost circular.
Inflorescence and flower
The flowering period extends from April to August and from October to January. At the end of a 3 to 10 millimeter long, in cross-section, pedicel-round inflorescence stem stands a composite inflorescence , which consists of dold-like partial inflorescences , each with about three flowers. The flower stalk is 1 to 6 millimeters long in cross section with a round stem.
The green to creamy white flower bud, which is not floured blue-green or frosted, is obovate to pear-shaped or even ovoid with a length of 6 to 10 millimeters and a diameter of 5 to 7 millimeters. The sepals form a calyptra that falls off early or remains in place until anthesis . The smooth calyptra is hemispherical and as wide as the smooth flower cup (hypanthium). The flowers are white or cream in color.
Fruit and seeds
The fruit stalk is 1 to 7 millimeters long. With a length of 8 to 15 millimeters and a diameter of 7 to 12 millimeters, the fruit is egg-shaped to urn-shaped and three-sided. The disc is indented, the fruit compartments are included.
The regular and flattened, kneecap-shaped or egg-shaped seed with a length of 2.3 to 5 millimeters has a net-like, matt to silk-matt, red or red-brown seed coat . The hilum is at the top of the seed.
Chromosome number
The number of chromosomes is 2n = 22 or 44.
Occurrence
The main distribution area of the lemon eucalyptus is the east coast of Australia, from northeastern New South Wales north of Coffs Harbor to northern Queensland north of Cooktown and the Great Dividing Range to the west . Also on the coast of southern New South Wales to and south of Sydney and in northern Victoria and around Adelaide in South Australia can be found sporadically Corymbia citriodora .
The lemon eucalyptus thrives in hard deciduous forests and light forests on lighter, loamy soils in hilly terrain.
Taxonomy
It was first published in 1848 by William Jackson Hooker under the name ( Basionym ) Eucalyptus citriodora Hook. in Journal of an Expedition into the Interior of Tropical Australia , p. 235. The new combination to Corymbia citriodora (Hook.) KDHill & LASJohnson took place in 1995 by Kenneth D. Hill and Lawrence Alexander Sidney Johnson under the title Systematic studies in the eucalypts, 7 A revision of the bloodwoods, genus Corymbia (Myrtaceae) in Telopea , Volume 6, Issue 2-3, p. 388. The specific epithet citriodora is made up of the Latin words citrus for lemon and odor for smell and indicates the smell of ground Leaves down. Other synonyms for Corymbia citriodora (Hook.) KDHill & LASJohnson are Eucalyptus melissiodora Lindl. , Eucalyptus maculata var. Citriodora (Hook.) FMBailey , Eucalyptus maculata var. Citriodora F.M.Bailey nom. illeg., Eucalyptus maculata var. citriodora Kinney nom. illeg., Eucalyptus variegata F.Muell. , Corymbia variegata (F. Muell.) KDHill & LASJohnson , Corymbia citriodora (Hook.) KDHill & LASJohnson subsp. citriodora and Corymbia citriodora subsp. variegata (F.Muell.) ARBean & MWMcDonald .
use
The lemon eucalyptus plays an important role in forestry and in honey production. It is used as an ornamental plant not only in Australia. There are varieties.
The heartwood is light brown to dark red brown and has a specific weight of around 1010 kg / m³. Like the wood from Corymbia henryi and Corymbia maculata , it is used as construction and furniture wood and is used, for example, in boat building and for the manufacture of tool handles, railway sleepers and floors.
The essential oil of lemon eucalyptus consists mainly (80%) of citronellal and is mainly produced in Brazil and China .
Individual evidence
- ↑ a b Specimen search results: Corymbia citriodora at Australia's Virtual Herbarium. Council of Heads of Australasian Herbaria . Retrieved February 19, 2013.
- ↑ a b c d e APNI = Australian Plant Name Index . Center for Plant Biodiversity Research. Australian Government. Retrieved February 19, 2013.
- ↑ a b c d e f g h i j k l m n o Corymbia citriodora at EucaLink - A Web Guide to the Eucalypts . Retrieved February 19, 2013.
- ↑ a b c d e f g h i j k l m n o Corymbia citriodora at EUCLID . Retrieved February 19, 2013.
- ↑ Eucalyptus citriodora at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ Corymbia citriodora at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed February 19, 2013.
- ↑ Rafaël Govaerts (ed.): Corymbia citriodora. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved February 19, 2013.
- ↑ Spotted Gum. Department of Agriculture, Fisheries and Forestry. Queensland Government. Retrieved February 10, 2016.
- ↑ DJ Boland et al .: Eucalyptus Leaf Oils - Use, Chemistry, Distillation and Marketing . ISBN 0-909605-69-6 . The source was available to the author of the article in the en: WP.
- ^ J. Lawless: The Illustrated Encyclopedia of Essential Oils . ISBN 1-85230-661-0 . The source was available to the author of the article in the en: WP.
